You're Level 85. You'd like to start raiding, or at least running some heroics. But you don't have the gear! How do you get the gear to go get the gear? Catch 22!
Fortunately, Blizzard has thought of that. And Silix over at Epic Diapers has thoughtfully put together a "how-to" on getting gear good enough to get you started. Silix does a segment on The Instance also; you should listen!