Hi Katie! Once you start your planning for your great Walt Disney World vacation things will start to fall into place. The first step is to decide your budget. Disney offers three different ranges for their resorts allowing you to choose great spots within your price point for the trip. I do STRONGLY recommend you stay on property as the benefits are great to help make the trip more magical. I will offer my choices for your age children within the three categories.
Deluxe: Polynesian resort or Wilderness Lodge (both close to the Magic Kingdom)
Moderate: Caribbean resort (Port Orleans is my favorite but most families opt for Caribbean)
Value: Pop Century (tends to have less groups)
You can see more information and pricing by clicking
HERE. You will find the Disney magic in each resort and the differences will be the amenities that are offered as well as more sophisticated themed pools at the deluxe locations. Also, the deluxe resorts offer restaurant dining which is often a nice option when you are traveling with small children. If you don't feel you will be in your room very often except to sleep then look at either the moderate or the value resorts.
Your next step will be to decide an itinerary. Decide what parks on what days and then see if you want to get some park dining. Those reservations fill up quickly so be sure and call for them on the first day possible. That timing in changing over to 180 days ahead in late October and stands at 90 days now. 407-939-3463 is the dining reservation number.
Each park offers many great opportunities for your children's ages. You can see the filtered list of what Disney recommends by clicking
HERE and then clicking on RECOMMENDED AGES at the bottom of the left side of that page. It's a great place to start making your park plans.