Hi Kristina:
I have a five year old and a four year old and have been traveling to Walt Disney World with them since they were infants. Your family may have different tastes, but hopefully these Magic Kingdom and Hollywood Studio recommendations will be a good start to planning your trip.
While only a portion of the many Magic Kingdom attractions, our family always enjoys it's a small world, Jungle Cruise, Mickey's PhilharMagic, Peter Pan's Flight, The Many Adventures of Winnie the Pooh, Pirate's of the Caribbean, Tomorrowland Transit Authority People Mover, and Monster's, Inc. Laugh Floor. If you think your little one would appreciate it, you can also check out Haunted Mansion. Our must-dos at Hollywood Studios include Toy Story Mania, Muppet Vision 3-D and the
Honey, I Shrunk the Kids Movie Set Adventure.
Check out the
Magical Beginnings map for tips and locations of rides and attractions suitable for kids five and under at all four Disney World theme parks.
As you enter the parks, pick up a Times Guide for parades and show schedules throughout the day. Since it's a first visit, check in at City Hall at the Magic Kingdom, or at guest relations at other parks, and pick up a "first-visit" button. Many Cast Members will go out of their way to greet your family with a kind gesture.
My best advice is to relax, follow your childrens' pace, and enjoy.