Be sure to show him some 'insider' stuff or things that the regular or first-time visitor probably doesn't know about. So show him a hidden mickey, lift up the phone in the hat shop, sample the sodas at club cool (I have heard from way too many people that they thought it was only for sale items in there, not free samples!), Cinderella's wishing well and rose garden, etc.
Of course, do all the ride classics, enjoy the unique food, and see the great shows. As someone who has been there before though, you can give him some 'insider' info!