We have always used the Birnbaum's for Kids with our kids, and they love it. They just graduated to the regular Birnbaum's, but still use their old kids' versions.
For our youngest (a pre-schooler,) I made a "book" in a word document on the computer. It describes things that he will do (using his name on most pages,) from the airplane to the hotel to the parks. After each brief phrase, I included a picture either from the internet or from our previous trips. So it's entirely personalized, uses language he understands best, and anticipates lots of situations. It helps to prepare him for things like rider swaps (when his older brothers will ride "tall rides"), meeting characters, etc. If you ask him what he will do if he gets tired, hungry, sad or needs to wait for his turn at Disney, he will tell you what he learned from his book!
He loves this book and wants to read it all the time!!!