Well you are in the right place to start looking. For the most part the tribes have posted their charters here in this thread. I would spend some time reading through the thread, reading about the tribes, deciding what kind of game you want this to be for you, find a tribe that supports your play style and follow their links. There are some great tribes that have taken hold in the game. Good luck, and if you have any questions about a tribe, you can always post to their tribal thread, if you have any questions about the game in general I'm sure you can find your way around the forums or just ask.