[EricH]

Aluminum (tube and angle, probably in the 1" square range)
Plywood/Lexan (anybody using acrylic/plexiglass is asking for a failure)
Fasteners
PVC in some cases
Pool Noodles. (These will be used in bumpers. Leftovers make decent shock absorbers for mechanisms that might hit the frame.)

Tools to work with above (saws, drills, drivers)


As far as sources, McMaster-Carr is a little expensive, but has very fast shipping. For stuff on the above list other than aluminum, the nearest home-improvement store should have it (though that might still be a long way)--bear in mind, you'll probably need a lot of plywood to build field elements as well as parts on the robot.

As a rookie team, I would not recommend doing anything overly complicated. Kitbot or Kitbot on Steroids drivetrain (you get all the parts for the former in the kit), a basic manipulator, and plenty of practice will serve you as well as anything more complicated.