Approaching the local school is a good first step.
There are a lot of good resources available for organizing and running a team on the FIRST site, especially:
http://www.usfirst.org/roboticsprogr....aspx?id=14034
Also, look under Marketing Resources.
Also, the NEMO (Non-Engineering mentor Organization) provides a lot of great resources:
http://www.firstnemo.org
There's a lot to starting and running an FRC team besides building robots. NEMO has an excellent forum here on Chief Delphi.
Good Luck! Let us know if you need help!