One of the best FREE screening services can be found in MSN MONEY, http://moneycentral.msn.com/home.asp
You can also visit Zack Research http://www.zacks.com/ and Morningstar http://screen.morningstar.com/StockResults.html
Both sites have predefined screens and they you the ability to design your own.
All of these sites provide free screening, and you can’t beat that price.
good luck