Free Discount Mailing ListThere are a TON of mailing lists out there that are free to sign up for and that provide you alerts about great discounts on hotel, airfare, Disney resorts and much more. I really suggest that you first create yourself a new email account at hotmail or gmail. Sign up that new account to the mailing lists. That way when you are done with your Disney vacation, you can see how much spam they've started to receive as a result of your mailing list sign-ups :)
Free Coupons and Discounts from DisneyWorld.com
The main Disney.go.com address. You don't tend to get a lot of coupons here, but you do get news and information about what's going on in the world of Disney.
Disney Shopping Site
You'll get alerts about special sales that you could be interested in.
I've done a number of trips that TravelZoo alerted me to. They really get some amazing deals. You have to catch them quickly though - they sell out literally within hours of an announcement.
Disney Discounts and Coupons
Disney Tips Main Page