Raiding is a coordinated dance of precision, strategy and not having anyone go afk unannounced. Not that I have done that. Ever. No, really. Ok, that one time, but it's not like we couldn't recover from the wipe in time to try again, right?
Anyway, the first time you attempt a raid boss, it's great fun seeing what the event has in store for you. But after that first time, it's incredibly irritating to wipe out time and again. There are strat guides for boss kills here and there about the Internet, but I found one site that collects them all in one place.
For every raid target in the game, BossKillers.com presents strat guides three different ways: they have an extensive strat guide written for their site; they have links to other popular strat guides for that boss; and they also have links to kill movies for each boss. For their own guide, it covers each phase of the fight including diagrams showing player placement, class roles with notes for different specs and gear requirements along with recommended buffs and consumables. If you don't agree with the strat, check out the many others they link to. Still having a problem visualizing the fight? Click on the many movie links they offer.
So next time you get ready to raid, you'll have no excuse to be unprepared for the big fight. If no one went afk unannounced.