My 8 year old likes the Birnbaun Guide for Kids. It gets her excited about the planning phase. I have used the Unofficial Guide, Birnbaum, and Intercot to plan all our trips. We have been 5 times and planning our 6th visit for this June. Every trip has been different and wonderful, which is why we keep going back. Here are things I skipped for the first trip, but did the 2nd time that we felt was a waste of time.
MK-Stitch's Great Escape(gross)
HS-Sounds Dangerous(boring)
AK-Flights of Wonder(neat, but too long, imo)
EP-Honey, I Shrunk the Audience(too dated)
Just my opinion.
Have fun! I hope you have a magical vacation.