Hi Brandy,
Planning a first trip to Disney World is awesome fun & its never too early to start. Disney has some wonderful resorts. They are all unique and there is a resort to fit every guest's needs no matter what you're looking for when selecting a "home" for your visit.
If having access to a great pool is one of your top priorities when choosing a resort, I'd suggest
Disney's Yacht or
Beach Club Resorts. These resorts share Stormalong Bay which is considered by many the best pool on property & offers 3 acres of aquatic fun for the whole family. This pool features the highest hotel waterslide at the Walt Disney World Resort. Another area features a shallow pool with a sandbar in the middle. Your kids will have a blast building sandcastles with their sand buckets & shovels that their lunch was served in from Hurricane Hanna's Grill. You can also rent a float and relax in the lazy river. They have pool activities for all ages.
The Yacht & Beach Club Resorts are also conveniently located near Epcot and Disney's Hollywood Studios which are easily accessible by Friendship Boat or walking.
Cape May Cafe at the Beach Club features a character breakfast buffet where your kids can meet Minnie, Goofy and Donald in their groovy beachwear.
If you plan to spend a majority of your theme park time at the Magic Kingdom, then I'd suggest staying at one of the resorts located along the Monorail Line. Disney's Grand Floridian and the Polynesian Resort both have good pools too. When my boys were that age, it was great to be able to pop over to our resort to take a pool or nap break before heading back to the Magic Kingdom for the evening.
Wishing you minnie magical memories :-) Allison