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.
[from Mousesavers]