They do have some discounted tickets for DL (as well as a few other theme parks). I didn't notice too much in a difference in price, compared to what DL prices were for online purchases, however they usually include one or two extras that are not available at the DL ticket booths (early entrance, free parking, etc) You would need to check with your local AAA office to see what their current prices and extras are.
Also, AAA members do receive a 20% discount on Disneyland tours. You can book DL tours up to a month in advance by calling (714) 781-4400. You can also book your tours right at City Hall. Be sure to let them know you have a AAA card. Their is a discount for Premium Annual Passholders, too. Not sure if it applies to other passholders or not. You would need to call to find out. Oh, you only get one discount or the other, you cannot apply both discounts to the tour.