Affliction Warlock
Rotation
Opener: Curse of Agony (or Curse of the Elements for a mage-heavy raid), Corruption, Siphon Life, Shadow Bolt.
Priority: Keep Corruption, Curse of Agony and Siphon Life ticking, Shadow Bolt as the filler, Drain Life to refill; Life Tap when the healers are comfortable. Dark Pact if the build has it.
Cooldowns: Amplify Curse before Curse of Agony; Death Coil as an emergency heal and interrupt; Howl of Terror to peel.
Forever notes: Affliction with a Voidwalker or Felhunter is the easiest leveling spec in the game and holds up in Forever's dungeons; Nightfall makes Shadow Bolt free.
Stats
Spell Hit to 16% (Suppression covers 5%), Shadow spell power (every dot scales), Spell Crit (Pandemic), Intellect, then Stamina for Life Tap room.
Stamina is a mana stat for Warlocks through Life Tap; do not gear like a Mage.
Numbers for every spec and a gear comparer: stat weights.
Where it ranks
See the tier lists for PvE and PvP placement, and Classic vs Forever changes for what Blizzard altered in this class.
Wowhead and Icy Veins keep spec guides of their own: Icy Veins Affliction Warlock, Wowhead class guides. Our rotation notes are editorial, written for the Nov 2 tuning.