I belong to
AAA South, so I don't know if the websites are the same - but here's how I do it:
I click on Travel, then Hotels. Where it asks for the city, I select Orlando from the drop down menu. At the bottom of the screen, where it lets you select a particular hotel chain, I select Disney World Hotels. Then it brings up just the Disney ones. I usually book room only, so I don't know how you would look up AAA Disney Packages.
Keep in mind that AAA will show both discounted availability, and after that, rack rate availability. Also AAA's rates are without the 12.5% resort tax (13% at All Star Resort). So if you are comparing AAA against Disney's website, you need to add the tax to compare totals (Disney's website does show the per night rate without tax, which makes it easier).
Also, I've found that AAA's website will only let you see availability one year ahead, so you won't be able to see November 2008 availability until December 2007.