I wouldn't actually build for the events now. I think that this time would be better spent learning some new stuff. There's time now to be crazy and to learn stuff. You won't have this much freedom once the season starts. It's also nice to set some goals when you're learning something.
For example, when I was first learning C, my goal was to complete an IRC client by the end of the summer. I sort of did, but it sucked. The point, however, was to use the goal as a way to learn. By trying to do a big project like that, I threw away all my bad C habits and really got to know how to do a lot of the things that you need to do in C.
Anyways, I went into PICs last summer, after growing out of BASIC Stamps. I went for AVR at first, but then PICs became more appealing once I realized that they're free, and a lot more people used it. Anyways, my project then was a quadrotor helicopter. In addition to the PIC experience I gained, I learned from that summer how to wind motors
, how to control brushless DC motors, and how to work with carbon fiber.
This year, I'm just going to try to finish that helicopter. Actually tying together all the electronics and hardware is probably going to give me some cuts, bruises, and burns. I'm hoping to gain lots of experience with control systems, maths, and batteries.
I might just finish that IRC client next year.