Hi Tracy,
What a wonderful way to spend your son's birthday, make sure you visit
HERE to sign him up for a special birthday gift during the year of "What will you Celebrate?"
There are so many things that you could do for your son, I found a great list of packages available
HERE. They vary from having your resort room decorated to getting special cakes. Cakes can be delivered to most Disney restaurants and I would highly recommend the new Disney Pirate Treasure Chest cake available at Character and buffet restaurants, it's so cute and the cake comes in it's own reusable chest.
Fun things to do for your son could be to send him on a Pirate Cruise at the Grand Floridian, get the "Cool Dude" package at Bibbidi Bobbidi Boutique, start pin trading or how about finding hidden Mickey's with him, it's a bit like Where's Waldo but you have to find the shape of Mickey's head hidden all over the parks, on rides etc it's fun for all ages and best of all it's free!
I hope I've given you a few ideas and he has the best birthday ever, oh also make sure you pick up a free birthday pin for him from concierge.
Jo