Hello! We will be traveling with 6yo, 3yo, 1yo in September to SSR. (Also with Me-Me and Papa) Any tips for this age group? It's our first family trip to Disney- can't wait!!!!
You should probably pick up a guidebook (or two)--our favorites are the Unofficial Guide to WDW and the PassPorter. This will help give you an idea of all there is to do in the World. From there you can decide what would be most important to your family. Try to do a couple of character meals--Chef Mickey's or Crystal Palace are our kids' favorites--this a great way to meet characters without waiting in line.
The first time we visited WDW DD#2 was 26 months old so to help prepare her for meeting the characters I bought the Disney sing-a-long videos. These, along with the vacation planning video, soon became her favorite videos to watch. The sing-a-longs are good because they show the characters interacting with kids as well as some scenes around WDW. We have Disneyland Fun, Camp Out at Walt Disney World, Beach Party at Walt Disney World and Flik's Musical Adventure at Disney's Animal Kingdom--I recently found these on DVD at Babies R Us.
Since you know your kids best, you will be the best judge of what your kids can handle. We did find that when DD#2 was younger she was more bothered by the loudness in the attractions than by the darkness. She HATED Honey, I Shrunk the Audience--she is now 5 and for the first time watched Polar Express in 3-D and wore the glasses. HISTA was the first 3-D attraction we tried at WDW and it traumatized both of our kids. I recommend Muppetvision 3-D for a less traumatic 3-D experience. Mickey's Philharmagic is good too but it can get a little loud. At that age she would watch the fireworks only if someone covered her ears. Some people suggest buying earplugs if your kids are really sensitive to loud noises.