In order to start raiding / raid progression, you need to snag the quest "The Fate of Norrath". Here's how:

* Fly to the City of Mist (Hidden Plunderers' Camp post) in Kunzar Jungle, and head due west along the river. Hug the wall to your right as you go, until you find a ramp going up. Take that ramp up and turn right heading to the loc: -214, 149, -1110 where you'll see a floating shield above some corpses. Investigate the battle scene.
* Collect the ?'s around the bodies. Should be about 3 of them.
* Look for a moppet laying on the ground.. mine was by a tree just east of the bodies.
* Now you'll need to find who the moppet belongs to. Go back to the river, and nearby there will be a cement bridge. Under this bridge there will be a door.. go inside and talk to the dude with the red book.
* You're now on the first tier raid zone.

NOTE: You may need to be level 80 to receive this quest.