Watch this clip from the Today show. They mention all kinds of websites to find out what's happening. Also, if you want the "inside scoop" on deals, go to the websites of the specific store or chain.
Don't forget to check Facebook, Twitter, etc. When you're on Facebook, be sure to "Like" the store to find out their deals!
If you aren't part of a social network like Facebook, maybe this is the time to get going!
Also, remember Cyber Monday!