Sorry to respond quick and then bail. Check out this link:

http://www.sheldonbrown.com/gloss_dr-z.html

Find "dropouts" on the page. It has examples of forged, stamped, and track ends, and the variations of each. Basically, forged dropouts are higher quality and generally are an indicator of the quality of the bike itself. I'm not saying that it's impossible to find a good bike with stamped dropouts (though a Schwinn won't likely be one of them), but it's sort of like using standover height as a check for fit. It won't be a pro fitting, but it's a great guideline if you don't know anything about buying a bike.