hambiskit is right on! Even better than a book would be an autobody course at your local community college or tech school. Quality auto body work takes time to learn, if it was easy the body shops would not have people lined up to $50-70 per hour to have thier cars repaired. The college course will be an enjoyable experience and you will learn the answers to all your question that would be impossible to answer well here.

Not trying to brush you off, just hoping to point you in a good direction

Pat