[EricH]

Other than direct drive? Well, I can only think of three or four.

Chain drive: run a chain to a sprocket that is attached to the wheel(s) you want to drive. It's a reliable connection if done right, and there's some "give" in the system.

Belt drive: See chain drive, but watch out for slipping. It's a little lighter.

Tank treads: Can put the tread through the gearbox if you want.

Gear drive: use gears instead of chains to link the wheels. Team 25 is one of the "expert" teams on doing this, IIRC.

As for the components and their uses, use your imagination.

Also, you might try searching for drivetrains, gearboxes, transmissions, and similar things both in the forums and in CD-Media.