If he had all the original parts, I'd say go ahead and put it back together. But, if you had to build it from scratch with new stuff, I wouldn't. First off, do you have any experience biking? Do you have any idea what you are doing? I'd at least go to borders or somewhere that teaches you how to build a bike. (You CAN really screw it up or cost yourself way more money that you should have.)

If you truly must build a bike, get a good frame. A Surly frame should be a good start.