Make sure you get a map and know the park's hours and show times. Depending on the day, the Magic Kingdom may open early or close late, giving you extra time to enjoy yourself in the park.
Use your map to find the attractions you don't want to miss, and figure out a plan. Everyone's favorite rides vary, but the most popular Magic Kingdom rides include Splash Mountain, Big Thunder Mountain Railroad and it's a small world.
Make sure you know the start times for any shows you want to see, including the fireworks. If you are planning on using FASTPASS, get your first one as soon as you enter the park.
The Magic Kingdom is divided into seven "lands," so work your way through the park by area. Do everything you want to do in one land, then move on to the next one, unless you have to leave for a show or to go use a FASTPASS.
Main Street, U.S.A., one of the areas, is mostly shopping and restaurants. Explore the area during some down time, or if all the ride lines are really long.
Afternoons in Florida can get very hot, especially during the summer, so if you need some time to sit and cool off, use the monorail.
The monorail leaves from outside the Magic Kingdom gates and travels to three hotels and Epcot, so you can see some different parts of Disney World while you relax. Make sure your park ticket allows re-entry before you leave the park to ride the monorail; you may need to get your hand stamped.