Check out the following resources:
www.firstrinos.com - FOR NEW TEAMs section
http://www.usfirst.org/community/frc...t.aspx?id=7006 - Resources for new teams
This manual can help you build a drive train that works. At the very least you will be able to score 2 points per lap.
Lastly, check out the white papers section on ChiefDelphi. Find the simplest stuff in there and implement it if appropriate.
MOEmentum is also a great resource (mentioned above).
Do not worry too much about all other departments of your team concentrate on getting the robot built in the simplest possible manner. Since you have only 15 students it might not be appropriate to have 10 different departments but rather maybe 2 or 3. Figure it out but keep it simple. You'll get through. The only people who can really help you in person are veteran teams/alumni in your area. Good luck.