Driving A 10x10x10 RGB Cube

it seems like he should probably make something smaller to get some practice with electronics, TLC5940s, Arduino programming, etc.

Let's face it. The OP is never going to make a 10 X 10 X 10 cube, it is one of those over ambitious things a newcomer wants to do. It is a lot more complex than just getting the right circuit and wiring it up. I wouldn't attempt this myself and I have got a bit of experience. I would say that there is over six months of work here.