World of Warcraft expansion and you boosted a character to the level cap. That's good. You also have no idea how to play that class at level 90, which is bad. A new series of videos from Blizzard is designed to address that problem, however, offering a quick two-minute guide to how to play each of the classes at level 90 as a selected DPS spec and walking you through the basic play patterns.
Yes, all of these guides are for DPS; you'll find no detailed tanking walkthroughs here. And each guide just picks a particular spec, so if you were hoping for insight into playing an Enhancement Shaman, you're out of luck. But if you've boosted a character and totally can't figure out what you're supposed to be doing now, it's a good crash course on playing well enough to fake it in LFR.