Aimee:
Our family just returned from Disney World and while we were there we celebrated our youngest child's 5th birthday.
I can say that both the Cast Members at the resort as well as the parks made him feel special from presenting him with the Birthday Button (they also have one for First Visit) to allowing him to punch the button the elevator....o.k. I know I'm not impressing you but my son, and I bet yours too, loved the attention...
It's hard to describe or even anticipate the kindnesses that will come your son's way while wearing his button (and remember to wear it, as Disney doesn't have ESP). On Main Street our family was stopped as the barbershop quartet sang not one version of "Happy Birthday" but three (well, it could have been because we couldn't get our camcorder to work....). At another attraction, our family was allowed to go first in the cue. It's not just what Disney does, but how they do it. They will make your youngster proud as a turkey. But don't anticipate the "free" kindness that may come your way, just enjoy.
Now, if we remove free and talk about things you can pay for to celebrate, I could fill your inbox for days. From a simple Mickey balloon to a a full-blown In-Room Celebration, check out Disney's recommendations
here. There may be some things you, too, may want to add to your first visit to make it special!
Wishing y'all a magical vacation!
Whitney