Claw will be your staple attack in kitty form until you get to level 50 and get Mangle. After you get Mangle, remove claw from your toolbar. Claw does damage, and adds a combo point towards a finishing move.
Rip
This finishing move puts a bleeding damage dot on your target. The more combo points, the greater the damage. When fighting something higher level than you, or heavily armored, Rip is valuable. Some critters, like elementals and the undead, are immune to Rip, since they don’t bleed, one assumes.
Prowl
The kitty is stealthed, making it less likely to be detected, and moving at a slower speed. Prowl is great to sneak about, and in most cases mobs and players your level and below won’t detect you. Prowl is improved by talents and by the Night Elf racial Shadowmeld.
Some of the kitty’s most powerful attacks can only be used from prowl.
Shred
This is very powerful attack that must be launched from behind the target. Thus, you will use it mostly in groups. Typically, with the tank holding the mob down, the kitty will position himself behind the mob and use the powerful Shred attack. Victims fleeing you in PVP also leave themselves open to a Shred. Shred takes a lot of energy, so you won’t be able to spam it like you can Mangle.

Tiger's Fury
Tiger’s Fury makes your next few attacks do increased damage. Many druids consider this a waste of energy. Still, it can be useful in some situations. If you need to polish something off fast, and have enough energy to pop a Tiger’s Fury and an attack, then Tiger’s Fury may be usefull.
Rake
Rake does a small amount of damage to a target, generates a combo point, and puts a bleeding dot on the target. Most feral druids use Rake very little. It is great to prevent a Rogue from using his Cloak of Shadows ability, and Rake can generate a combo point for less energy than a Mangle.
Dash
At its top level, Dash allows the kitty to run a 70% speed for 15 seconds. That’s faster than a regular mount can go. Dash is great in PVP, to get away or to pull something down. Dash is great when soloing to get out of trouble. You won’t use Dash much in groups; you’ll mostly use it to run for the exit to avoid a wipe.
Cower
Every melee class needs a way to reduce agro. Cower is the kitty’s answer. If you’ve pulled a mob away from the tank, hit a Cower to give the tank a chance to get control back. Cower has a small energy cost, so if you’re monitoring the threat meter and you’re approaching second place on the hate list, hit a pre-emptive Cower to move your threat back down.
Track Humanoids
This toggled ability uses no Energy and places dots on the minimap to display all nearby humanoids and players. Track Humanoids is great in PVP for several different reasons. You can also locate named mobs or quest mobs when soloing. Just be sure to turn it on if you’ve been tracking something else!

Ravage
A Ravage attack is your most powerful non-finishing move attack. You must be prowling and behind the enemy to get this off. Ravage is great in PVP and when soloing. In groups a Ravage might pull agro from the tank.
With high crit chance gear and popping a Tiger’s Fury before a Ravage, your kitty’s Ravage will hit some amazing numbers, sometimes dropping a cloth wearer in one shot. And that, my friend, never fails to satisfy.
Ferocious Bite
This finishing move converts all your Combo Points and all your energy bar into a single burst of damage. So it can do amazing damage, but it leaves you unable to get of another special attack until your energy bar recharges.
Consider your situation, and decide between Rip and Ferocious Bite as the finishing move. Rip is best when your target still has lots of health or is wearing armor. FB is best when your target is low on health.
Pounce
Pounce may turn into your favorite attack. A Pounce must be launched from stealth (being behind the target is not required). Pounce stuns the enemy and adds a bleed dot. A Mangle will add damage to the Pounce dot. Pounce is great in PVP, when soloing, and in groups.
Feline Grace
This passive ability reduces the amount of damage the kitty takes from falling. This has all kinds of uses. One of the best is in Arathai Basin PVP; you can jump off the cliff facing the Mine and launch an attack or capture the flag.
Maim
Main is a finishing move that does some damage and stuns the target (the more combo points, the more the damage and the longer the stun.) Its great for PVP and soloing. One great use is to stop a spellcaster from completing a spell. You can also Maim your enemy then pop into caster form to heal yourself.