Pneumatics, Pneumatics, Pneumatics!
Pneumatics are very easy, reliable, tollerable. They don't fail as often as a motor because they aren't relying on gears or sprokets or whatever. Anyway, I could suggest using pneumatics if you can for some of the simple mechanisms you add to the drive train. You could easily make a plow with some pneumatics - just have little arms/wings that swing out and then put a cylinder on them. If you need help with the pneumatics, don't forget to check out the manual posted online on FIRST's site - it's very good.
Best of luck - to you and all rookies! Keep with it guys - the best feeling is seeing your robot move on the field the first time (even if it is July instead of March!
).