Black Friday is poised to start on Thanksgiving this year. But is the annual retail salesfest encroaching too far on the American institutions of family and football that usually mark Turkey Day?

Retailers have been taking Thanksgiving away from employees by starting the sales earlier and earlier over the last couple of years. Kmart was the first to do this several years ago by opening on Thanksgiving. Now others like Target, Wal-Mart, and Toys R Us are following suit.

Target will open stores at 9 .m. on Thanksgiving for Black Friday sales. But they're being bested by Sears and Wal-Mart, both of which will open at 8 p.m.

Retailers used to get upset when copies of their Black Friday ads leaked out on the web. Today, however, they strategically leak them to websites like DealNews.com, BlackFriday.info, GottaDeal.com and BFAds.net, among others.

Wal-Mart in particular will be selling 60-inch LED TVs at $599 and a 15.6-inch laptop for $179.

One thing to beware of no matter which store you shop: There will be a lot of "high-low" pricing this shopping season. Lots of merchandise that's not normally stocked by a retailer will be brought in just for the weekend. It will not be bargain priced, though you will see signs everywhere screaming about sales.

You have to know your prices to know if you're getting a good deal!