Old Champ calls New Champ, and the first person to claim after the call is the Champ
The first six suggestions after the Champ claim is the team
Champ builds the team, either exactly as the set suggestion or to their discretion if it's just a Pokemon name
Champ posts the battle, or someone does if Champ forgets
Champ can call for a new team or a new champ after their done Champing, and the cycle begins again

It is suggested that you lurk and watch some battles before becoming Champ, so you become familiar with the rules and stuff.

Commonly suggested mons: http://pastebin.com/0bYpM0at
Fanart and caps: http://booru.showderp.com/
Plug DJ: http://plug.dj/showderp-1/