Once upon a time all you had to do to learn the tactics was play. Wiping on bosses and the depression of death, failure and repair bills can be a great motivator. At the same time, there are few unique boss fights in WoW. They all follow some kind of pattern and sometimes phases are even borrowed from other mobs. Others, such as Shade of Aran's Flame Wreath go down in lore and legend, even getting their own ever-so-catchy (nay beautiful) theme tune. I challenge anyone to move after having heard that (I even have that in iTunes and would play it just in case my raid forgot. No one ever did.).
So I wonder, constant readers, how do you learn tactics? I can read WoWwiki, for example, until I'm blue in the face but because of the weird way my brain is wired (don't ask), the only was I can truly learn tactics is in the fight itself. Yes, there's YouTube, there's the pre-boss-fight sit down where the raid leader does a run though the fight because no one bothered to take ten minutes to do some reading up. What methods do you use?