I used to book packages thru AAA for our first few trips, since we always camped before and I hadn't booked things like this. After finding this site I started booking everything myself. By booking room only ressie through Disney on the phone, I don't have to pay anything but one nights deposit on the room and have a 5 day cancellation window. With AAA packages you have to pay a deposit when booking and the rest is due 45 days before with hefty cancellation policy which is why they Sell you trip cancellation insurance (which of course has many reasons why they may not honor your excuse for cancellation). I also like having the money in my account earning interest and paying the room when we get there rather than in their account for 45 days. I have also booked the Autotrain online myself. They have a AAA discount too.
The more you read these boards the more you will learn.