You have to make a thread in a the trainer status subforum, so we can keep track of your team. You can't change the team you use at any time during the course of your adventure. Also, remember that ubers are banned. Any attempt to change your team will result in a loss of all the gym badges you have obtained.

Here's the link to the thread.
http://www.gaiaonline.com/guilds/viewforum.php?f=402503