Weapon Guide
As a mage you will be relying on your spells for you damage and not your weapon. So your weapon slot is only useful as a stats booster. There are two different weapon styles most mages use. You can either use a two handed staff, or a one handed weapon like a dagger or sword, and an item in your offhand. Prior to level sixty you will want to use a staff. There are very few good main hand and off hand items for a mage at this point while mage staffs are plentiful. Post sixty though you can use either. I personally prefer using a main hand off hand combo because it allows more customization for my gear. If I want more spell damage instead of crit, or more intellect instead of stamina I can switch in a new main hand or off hand to suit my need. While with a staff I have no real choice.
Armor Guide
Your armor is your primary way of increasing your stats. And the quality of your equipment will determine your effectiveness as a mage. While it would be nice if you could spread your stats out evenly, that is rarely ever possible. Most gear will rarely have more then three different stats or modifiers. The more they have the fewer each one will be so it isn't overpowered.
Different play styles will require different types of gear. Arcane mages need lots of intellect because their mana consumption is so high, but also need a good amount of spell damage and crit. Fire mages focus almost exclusively on spell damage on their gear because fire crits are complicated by Ignite and there are many talents in the fire tree that increase your crit chance. Frost is somewhat tricky. The longer the fight drags on the less useful spell crit becomes because of talents like shatter and Winter's Chill. Spell damage is slightly better than crit in my opinion, but try to balance out the two, especially if you are going to do group play.
Equipment By Level
Until about level fourteen nearly all of the equipment you have access to is either white quality or very weak green quality. There are also almost no blue quality weapons or armor till this point either. But because you level up so quickly it would be a waste of money to get expensive blue items at this point. At this early level look for “of the eagle” gear or gear with stamina and intellect. At this point it is best to avoid gear with “of --- wrath” for now, but if you find spell damage gear with other stats as well try to get it.
Level 20-29
Armor
Lavishly Jeweled Ring(Deadmines)
http://wow.allakhazam.com/db/item.html?witem=1156
Coirsair Overshirt(DM)
http://wow.allakhazam.com/db/item.html?witem=5202;source=live
Magician's Mantle (BOE)
http://wow.allakhazam.com/db/item.html?source=live;witem=12998
Spidersilk Boots (Craft)
http://wow.allakhazam.com/db/item.html?source=live;witem=4320
Feline Mantel (SFK)
http://wow.allakhazam.com/db/item.html?witem=3748
Robes of Argual (SFK)
http://wow.allakhazam.com/db/item.html?witem=6324
Belt of Argual (SFK)
http://wow.allakhazam.com/db/item.html?witem=6392
Batwing Mantle (RFK)
http://wow.allakhazam.com/db/item.html?witem=6697
Weapons
Staff of Westfall (Quest)
http://wow.allakhazam.com/db/item.html?witem=2042
Crescent Staff (Quest)
http://wow.allakhazam.com/db/item.html?witem=6505
Level 29-39
Armor
Acidic Walkers (Gng)
http://wow.allakhazam.com/db/item.html?witem=9454
Bloodmage Mantle (SM)
http://wow.allakhazam.com/db/item.html?witem=7684
Mantel of Doan (SM)
http://wow.allakhazam.com/db/item.html?witem=7712
Whitemane's Chapeau (SM)
http://wow.allakhazam.com/db/item.html?witem=7720
Robe of the Lich (RFD)
http://wow.allakhazam.com/db/item.html?witem=10762
Robe of the Magi (BOE)
http://wow.allakhazam.com/db/item.html?source=live;witem=4320
Corpseshroud (BOE)
http://wow.allakhazam.com/db/item.html?source=live;witem=10574
Weapon
Orb of the Forgotten Sear (SM)
http://wow.allakhazam.com/db/item.html?witem=7685
Illusionary Rod (SM)
http://wow.allakhazam.com/db/item.html?witem=7713
Hypnotic Blade (SM)
http://wow.allakhazam.com/db/item.html?witem=7714
Level 39-49
Armor
Grimlock's Tribal Vestments( ULD)
http://wow.allakhazam.com/db/item.html?witem=9415
Stoneweaver Leggings (ULD)
http://wow.allakhazam.com/db/item.html?witem=9407
Saytermane Sash(MARA)
http://wow.allakhazam.com/db/item.html?witem=17755
Vinerot Sandels(MARA)
http://wow.allakhazam.com/db/item.html?witem=17748
Forgotten Wraps (BOE)
http://wow.allakhazam.com/db/item.html?source=live;witem=9433
Dreamweave Vest (Craft)
http://wow.allakhazam.com/db/item.html?source=live;witem=10021
Dreamweave Circlet (Craft)
http://wow.allakhazam.com/db/item.html?witem=10041;source=live
Dreamweave Gloves (Craft
http://wow.allakhazam.com/db/item.html?source=live;witem=10019
Arena Wristgaurds (BOE)
http://wow.allakhazam.com/db/item.html?source=live;witem=18709
Weapons
Zumrah's Vexing Cane (ZF)
http://wow.allakhazam.com/db/item.html?witem=18082
Cloudstone(MARA)
http://wow.allakhazam.com/db/item.html?witem=17737
Inventer's Focal Sword(Mara)
http://wow.allakhazam.com/db/item.html?witem=17719
Level 49-59
Armor
Emerald Crown of Destruction(Craft)
http://wow.allakhazam.com/db/item.html?source=live;witem=21774
Featherskin Cape (ST)
http://wow.allakhazam.com/db/item.html?witem=10843
Atal'ai Gloves (ST)
http://wow.allakhazam.com/db/item.html?witem=10787
Dawnspire Cord (ST)
http://wow.allakhazam.com/db/item.html?witem=12466
Kilt of the Atal'ai Prophet (ST)
http://wow.allakhazam.com/db/item.html?witem=10807
Gloves of the Atal'ai Prophet (ST)
http://wow.allakhazam.com/db/item.html?witem=10808
Vestments of the Atal'ai Prophet (ST)
http://wow.allakhazam.com/db/item.html?witem=10806
Gemburst Circlet (Quest)
http://wow.allakhazam.com/db/item.html?witem=10751
Spiritcaster Cape(BRD)
http://wow.allakhazam.com/db/item.html?witem=11623
Chief Architect Monocle (BRD)
http://wow.allakhazam.com/db/item.html?witem=11839
Robes of the Royal Crown. (BRD)
http://wow.allakhazam.com/db/item.html?witem=11924
Songstone of Ironforge(Quest)
http://wow.allakhazam.com/db/item.html?witem=12543
Eye of Ogrinmar (Quest)
http://wow.allakhazam.com/db/item.html?witem=12545
Crimson Felt Hat (STRAT)
http://wow.allakhazam.com/db/item.html?witem=18727
Thuzadin Sash (STRAT)
http://wow.allakhazam.com/db/item.html?witem=18740
Diana's Pearl Necklace(STRAT)
http://wow.allakhazam.com/db/item.html?witem=22403
Shroud of the Nathrizim. (STRAT)
http://wow.allakhazam.com/db/item.html?witem=18720
Weapon
Resurgence Rod (Quest)
http://wow.allakhazam.com/db/item.html?witem=17743
Spire of Hakkar (ST)
http://wow.allakhazam.com/db/item.html?witem=10844
Drakestone (ST)
http://wow.allakhazam.com/db/item.html?witem=10796
Rod of Corrosion (ST)
http://wow.allakhazam.com/db/item.html?witem=10836
Kindling Staff (BRD)
http://wow.allakhazam.com/db/item.html?witem=11750
Level 60-62
Armor
Destroyer's Mantle (Quest)
http://wow.allakhazam.com/db/item.html?witem=28075
Mantle of Magical Might(Quest)
http://wow.allakhazam.com/db/item.html?witem=25718;source=live
Shadowcast Tunic (Quest)
http://wow.allakhazam.com/db/item.html?witem=28075
Arcing Bracers (BF)
http://wow.allakhazam.com/db/item.html?witem=24392;source=live
Mindfire waistband (BF)
http://wow.allakhazam.com/db/item.html?witem=24395;source=live
Vengeance of the Illadari (Quest)
http://wow.allakhazam.com/db/item.html?witem=28040
Witching Band(RMP)
http://wow.allakhazam.com/db/item.html?witem=24154;source=live
Weapons
Crystalfire Staff (RMP)
http://wow.allakhazam.com/db/item.html?witem=24069;source=live
Spellfire Longsword
http://wow.allakhazam.com/db/item.html?witem=24361;source=live
Level 63-64
Armor
Spore-soaked Venear (SP)
http://wow.allakhazam.com/db/item.html?witem=24362;source=live
Luminous Pearls of insight(UB)
http://wow.allakhazam.com/db/item.html?witem=24462;source=live
Amulet of unstable power(SP)
http://wow.allakhazam.com/db/item.html?witem=31178;source=live
Robes of the Auger(Quest)
http://wow.allakhazam.com/db/item.html?witem=24481;source=live
Boots of the Skystrder(MT)
http://wow.allakhazam.com/db/item.html?witem=25957;source=live
Weapon
Reveared mother's Crystal Knife(Quest)
http://wow.allakhazam.com/db/item.html?witem=31758;source=live
Zanagertooth Shortblade(UB)
http://wow.allakhazam.com/db/item.html?witem=24453;source=live
Staff of Polarities(MT)
http://wow.allakhazam.com/db/item.html?witem=25950;source=live
Voidfire Wand(MT)
http://wow.allakhazam.com/db/item.html?witem=25939;source=live
Level 65-66
Armor
Consortium Princes Wrap(Quest)
http://wow.allakhazam.com/db/item.html?witem=29328;source=live
Aucharai Anchorite's Robe(Quest)
http://wow.allakhazam.com/db/item.html?witem=29341;source=live
Tempest Touch(Quest)
http://wow.allakhazam.com/db/item.html?witem=29317;source=live
Torc of the Sethek Prophet(Quest)
http://wow.allakhazam.com/db/item.html?witem=29333;source=live
Burning Blade Cultist Band(Quest)
http://wow.allakhazam.com/db/item.html?witem=25607;source=live
Weapon
The Saga of Terrok(Quest)
http://wow.allakhazam.com/db/item.html?witem=29330;source=live
Battle mages Baton(Quest)
http://wow.allakhazam.com/db/item.html?witem=25760;source=live
Nessingwary's Safari Stick.(Quest)
http://wow.allakhazam.com/db/item.html?witem=25640;source=live
Level 67-68
Armor
Tourmaline Crown(Quest)
http://wow.allakhazam.com/db/item.html?witem=31546;source=live
Natasha's Ember Necklace (Quest)
http://wow.allakhazam.com/db/item.html?witem=31692;source=live
Cloak of Woven Energy(Quest)
http://wow.allakhazam.com/db/item.html?witem=29813;source=live
Weapon
Ameer's Impulse Taser
http://wow.allakhazam.com/db/item.html?witem=30011;source=live
Level 69-70
Armor
A'dal's Gift (Quest)
http://wow.allakhazam.com/db/item.html?witem=31461;source=live
Gloves of the High Magus(Quest)
http://wow.allakhazam.com/db/item.html?witem=30924;source=live
Spaulders of the Torn Heart(Quest)
http://wow.allakhazam.com/db/item.html?witem=30925;source=live
Evoker's Helmet of Second Sight (Quest)
http://wow.allakhazam.com/db/item.html?witem=31104;source=live
Evoker's mark of the Redemption(Quest)
http://wow.allakhazam.com/db/item.html?witem=31075;source=live
Bands of Nethacurse(SH)
http://wow.allakhazam.com/db/item.html?witem=27517;source=live
Sash of Serpenta(SV)
http://wow.allakhazam.com/db/item.html?witem=27795;source=live
Shiffar's Nexus Horn (ARC)
http://wow.allakhazam.com/db/item.html?witem=28418;source=live
Devil Stitched Leggings(BOT)
http://wow.allakhazam.com/db/item.html?witem=28338;source=live
Baba's Cloak of Arcanistry(MECH)
http://wow.allakhazam.com/db/item.html?witem=28269;source=live
Warp Infused Drape(BOT)
http://wow.allakhazam.com/db/item.html?witem=28342;source=live
Weapon
Netherwing Sorcerer's Charm(Quest)
http://wow.allakhazam.com/db/item.html?witem=31494;source=live
Runesong Dager(SH)
http://wow.allakhazam.com/db/item.html?witem=27868;source=live
Greatsword of Horrid Dreams(SL)
http://wow.allakhazam.com/db/item.html?witem=27905;source=live
Manual of the Nethermancer(MECH)
http://wow.allakhazam.com/db/item.html?witem=28260;source=live
Lamp of Peaceful Radiance(ARC)
http://wow.allakhazam.com/db/item.html?witem=28412;source=live
Gems
After level sixty many high level items contain gem sockets that you can use to augment your gear further and customize your playing style. Gems come in three different types. Pure colored gems like red, yellow and blue focus exclusively on one stat like strength, crit or healing. Most of the time you will want to focus on these types of gems when socketing your armor. This lets you maximize a certain stat that you are low on like +healing or attack power. Mixed color gems are a combination of two primary gems. So a purple gem might have a red gems +spell damage and a blue gems +stamina. In order to not be overpowered mixed gems always have have the power of a pure colored gem, but its strength is spread out over two slots. For the most part you will only want to use a mixed color gem if you are trying to complete a socket bonus, or want to raise two attributes evenly. The final catigory of gems are meta gems. These can only be equipped in head armor and have a special effect besides just boosting your stats. They also require a certain condition be met before being activated like having a certain number of colored gems, or more of one color than another.
Socket Bonuses.
The sockets on a piece of gear will correspond to one of the three primary colors. If you match the color of the gem with the socket most armor will give you a socket bonus of some extra strength or spell damage or stamina. You don't need to match the sockets with the color of your gems, but if you do you won't gain the bonus. For the most part though socket bonuses are not very worthwhile. In order to get a socket bonus you may need to use gems that don't fit very well with your playstyle, where as if you ignore the bonus and put in the gems you want you will usually gain a larger bonus to the stat you most want.
Raiding Gems.
When raiding you will want to focus on spell damage, crit and hit.
Red slots should be filled with Runed gems for maximum spell damage. Veiled is a good alternative for a mixed gem if your spell damage is high and you need spell hit.
Yellow slots should either have Gleaming gems for crit, or Great gems for hit. Once you have reached a hit rating of 15% don't bother getting more and instead get Gleaming.
Blue slots normally have stamina, but since you don't need that in a raid either get mana per five gems like Lustrous. Or you can get mixed gems like Sovereign gems for a bit more spell damage.
PVP gems
When PVPing you will want to focus on stamina and resilience, but also keep up your crit and damage rating.
Red Sockets should usually be filled with mixed gems because the only pure gem that helps a mage is Runed +damage. Potent gems are a good choice with spell crit and damage, but Glowing gems are good as well if you need more stamina.
Yellow sockets should either have Gleaming gems for crit or Potent for a mix of crit and damage. You can also use Mystic if you have not reached the resilience cap.
Blue slots can be filled with pure Solid stamina gems, but I only do this if I am really low on stamina. I try to use mixed gems that also give resilience like Steady.