Some more papers that may be helpful:
Universal Drive Systems This paper covers many of the various drive systems around. Its a tad out of date (no mecanum) and doesn't go into a lot of detail, but it is a GREAT paper to start with. There also used to be some very nice drive system papers on the Innovation First site that supplement this file quite well, but they nolonger appear to be there.
C Programming and Autonomous Modes for Newbies This paper provides a great introduction into C.
For manipulators, the "Designing Competitive Manipulators: The Mechanics & Strategy" ppt found in the 2006 Championship workshop archives (Second link Lil' Lavery posted) is quite good.
For electrical things, the whitepapers at Innovation First's website will give you the basics of the Victors and Spikes, and the wiring diagram that FIRST puts out every year will give the overall view.
And last, but certainly not least, the Guidelines, Tips, and Good Practices document that FIRST has along with the manual every year is an excellent source of general stuff about building/designing your robot.