I only know a little bit... If you want to have an officially recognized club you need to register it with USA cycling. (www.usacycling.org may be able to give you some more information, but it may not be easy to tease out of all of the stuff on the site...) some good info on this page.. http://www.usacycling.org/news/user/story.php?id=91

Doing this has some benefits and responsibilities. If you register your club you can race in team kit with sponsors (otherwise you can only have plain kit or just your team name and would still be considered an unattached rider), but as far as I know your club also has to put on one event per year to retain its club status - small clubs can co-sponsor events - or at least I've seen it done around here. Around here we also have professional race organizers that do a lot of the work - the team then supplies its name and lots of volunteers to work the race.