Hi Denise:
I'm a parent of two boys, ages 5 and 3, and we always enjoy all of the theme parks at Walt Disney World. I would love to share some of my family's must-dos for our Disney World vacations. Your family may have different tastes, but hopefully these recommendations will be a good start to planning your trip.
For certain, I would take your family to Magic Kingdom. Among many other things, at the Magic Kingdom, we always ride the Jungle Cruise, Peter Pan's Flight, Mickey's PhilharMagic, and it's a small world. At Epcot, we take in Spaceship Earth, Living with the Land, and tour the countries of World Showcase. Our must-dos at Hollywood Studios include Toy Story Mania and Muppet Vision 3-D. At Animal Kingdom, our family always rides the Kilimanjaro Safari and visits The Boneyard and Conservation Station.
Of course, every family is different, and to have a successful trip, you will have to take your grandchildren's likes, dislikes, and comfort-level into account. As you enter the parks, pick up a Times Guide for parades and show schedules throughout the day.
Also, I recommend having a look at
Disney's in-depth planning page for traveling to Walt Disney World with younger children, including having a look at the
Magical Beginnings Guide for maps and more tips.