The Chess Thread
Get this book: Chess Fundamentals by Capablanca. It is not expensive and its teachings are ageless golden. You read a section and then work with your son on what you learn. This book emphasizes a lot on end games which many beginners do not like. But practice endgame is like building up your endurance in playing football. Very important.
Secondly, open an account for him in Yahoo Chess. Let him rip.