This is taken from the Mousesavers website. It specificies the type of discount you'll get using AAA.
AAA and CAA Resort Hotel Discounts
American Automobile Association (AAA) and Canadian Automobile Association (CAA) members qualify for "room only" discounts almost year-round, though there are a limited number of rooms available for each date. You can generally save about 10-20% at the Disney resort hotels, depending on the season.
In general, the discounts run as follows:
During Value Season you can get up to 15% off at the Disney Deluxe and Disney Vacation Club resorts, or 20% off at the Value and Moderate resorts and the Ft. Wilderness campsites.
During Regular Season you can usually get up to 10% off at the Disney Deluxe and Disney Vacation Club resorts, or 15% off at the Value and Moderate resorts and the Ft. Wilderness campsites.
During Peak Season and Summer Season you can usually get up to 10% off at the Disney Deluxe and Disney Vacation Club resorts, or 15% off at the Value and Moderate resorts.
The only time AAA/CAA discounts don't usually apply is Holiday Season (around Christmas) at the Value and Moderate resorts.