I want a mic, $50-100, for simple recording of band practice. Maybe a stereo mic to seperate the two guitars. We are a loud rockband. Suggestions?

Don't know much about stereo mics, but you might be able to locate a couple used Shure SM-57's for near your budget. I think these are an excellent choice for your first mic pair. If you decide to later upgrade to better mics, you'll still probably find uses for this very versatile mic. I own over 40 mics and still occasionally select one of my 57's over some that cost much more.

This link seems to have at least some info that might be helpful to ya:
http://www.google.com/search?hl=en&rlz=1T4DMUS_enUS221US222&q=Recording++room+mics+%24100&btnG=Search

Here's a couple recording sites I learned allot at:
http://homerecording.com/bbs/
http://www.gearslutz.com/board/
http://www.badmuckingfastard.com/sound/slipperman.html

Good luck with those recordings man...

If a loud band then I don't think there are stereo mic's in that price range that will do the job. Get a couple Shure mic's 57's or 58's are good utility mic's and can handle high SPL levels. The 57 is more of an instrument mic, but it's pattern is designed more for close mic'ing. The 58's is designed more for vocals, but can be used on about anything. It has a more open pattern which would probably work better for what you are wanting to do.