Are you referring to the AQ's? These scale to the type of armor you use. What I mean is that if you are a Guardian and you undertake these quests, you will get plate. If you are a Monk, you will get medium, etc. etc.
If so, the quests are available at level 20 and you get them from Ian Ironforge in Qeynos Harbor for good and Dyric Pire in East Freeport for evil.