Hi Shelley!
My opinion is that, for most three year olds, Walt Disney World is the perfect family vacation destination! Each member of your family can find something to do that he/she will enjoy while there, as there really is something for everyone.
Your vacation will be made even simpler by knowing that when you're at Walt Disney World, many things have already been taken into consideration for families visiting with little ones. There are baby care centers for the little ones at the theme parks. Strollers are available for rent in the theme parks. You can find all sorts of food to feed your family, too. There are fruits stands at the parks for snacks, and plenty of kid friendly meal options at the various restaurants. Also, Walt Disney World resorts have cribs available, you just need to make your requests upon making reservations and/or checking in.
Your little one will also find that there are so many attractions for him to enjoy as he explores the park, too. I often suggest looking over highlighted attractions on the maps available
here, which are intended for families with little ones.
Most importantly though, I believe in living in the moment, and making the most of those memorable vacations with your precious family. Your son may be three years old, but the little ones I've seen at Walt Disney World are in awe of the magic all around them. They take it in, and remind the older family members of just how special the Walt Disney World touches are, and you will always remember their priceless reactions to their first view of Cinderella Castle, or their first meet and greet with their favorite Disney character.
With a little preparation, and help from the Moms Panel along the way,
you can plan for this to be your most magical, and memorable, family
vacation yet.