The following may be helpful if your team is using Java or C++. (They're written in Java, but the concepts translate.)
To introduce new students to Java and programming in general, we used
Robocode. Exactly how helpful this is could vary, but I think it's a very cool tool and can be very educational, especially if you have a person or two on your team who knows some programming already. One thing it does very, very well is get people who don't see themselves as computer nerds interested in programming (kind of like FRC does for engineering in general). Their site has a few useful links.
At kickoff, I gave
this presentation, the second half of which is a quick introduction to WPILib in Java and the command-subsystem programming paradigm. For more detail, you'll want the WPILib cookbook or the actual javadoc, but I don't think you want to throw those things straight at new programmers.
Good luck! Tell us all how everything goes!