This is a different flavor of off-season event, but I might suggest you check out what we do with BunnyBots at
www.team1540.org/bunnybots. Basically our alumni make up an FRC-style game, and we have a 12 week build season to make a robot, which gives a great opportunity for rookie members and teams to learn most everything they need for FRC in a more relaxed, but still FRC-like, environment. For a better visual of competition day, here's a video of last year's final matches
http://www.youtube.com/watch?v=4gX5szIwyvQ.
It might be a bit too late for this year (but maybe not!), but if you're interested in starting something like this in your area, drop me a line. We already have Washington state and Colorado onboard with their own events for the first time this year - this is our 6th year doing BunnyBots in Portland, OR. We try to make the game design so the field is easy to make and host.