The main site that I've used for years is BFAds.net which posts official and unofficial Black Friday ads as they become available. They also categorize the ad based on item type, such as Electronics, Clothing, etc. They also post which items are "Door busters" (typically high demand items that are limited in quantity) and the times at which the different retailers open their doors. There has been an emerging trend where different retailers are opening earlier and earlier to one-up each other for our consumer dollars. Nowadays, a 4AM store opening is considered pretty late. Alternatively, Slick Deals has also started their own Black Friday section with much of the same information, although their main focus is on deals going on today (as shown in the deals listed on the right).
Once you've found which retailer will sell your desired item, you can see how much of a deal the Black Friday sale actually is. It's a good thing you've done your Preparation ahead of time, as you know how much you can get those items for today. Who knows? Maybe you'd be able to avoid a store altogether because you can get a comparable deal for an item today. Remember, just because it's on sale on Black Friday, doesn't make it a good deal.
Additionally, you can use these sites to determine what else that retailer is selling on Black Friday. If you're gonna be waiting on line for hours anyways, you might as well pick up a few good deals as well.
Back to Preparation.
Next time, Scheduling.