Just posted some lore, with an introduction to some of the factions you can choose.
Soon, I'll post information on the Crusader Kings style council, and you'll be able to claim which position looks best to you. Claims are done on a fist come first serve basis, and only one player can have a individual position. There'll be other kinds of characters, though, such as nobles and merchants, who won't be restricted like this.
Sorry if this overcomplicates things, let me know if it does, or if I haven't explained properly.