Beatdown Brigade!

Useful WoW-related links:

Official World of Warcraft site

WoWHead - currently preeminent WoW database

WoWAce - addon clearinghouse

Deadly Boss Mods - boss mod suite for raiding

Curse Gaming - User Interface modifications database

Official Skullcrusher realm forum - trolling & drama
     Server progression thread

WoWWiki - useful for historical info & lore

Elitist Jerks forums - preeminent source for WoW PVE information
     Class Mechanics discussion forum on EJ
     'Theorycrafting Think Tank' on EJ - fundamental compilations of info for various classes/specs

Arena Junkies - Forum & resource for PVP strategy and discussion