Multi-site Install on Ipowerweb

I've installed drupal 5x on my root directory. It works well; however, I want to add another site (www.main-site.com/site2). I want this site to run off of a separate database. I created both databases (site 1 works beautifully). I tried installing drupal in the folder at /site2. When I ran the install there, I couldn't login again on main-site.com. The page stated it couldn't connect to the database. From there, I tried a to add another site following some of the directions in the handbook and forum. The difference is that I don't want people to share logins, nor do I want to share databases. I created /sites/main-site.com.site2 and configured the setup.php file. When I direct my browser to www.main-site.com/site2 it states there is no index file.

1. Is there a way to install multiple codebases and install multiple sites without one site cancelling out the other site? I think this seems like an easier thing to do and in my realm of knowledge. This htaccess, etc. stuff (like I think might be required to fix my problem) is probably a little over my head.

2. If I'm on the right path to installing this multi-site ability of drupal, what do I do to get my install to work?

This can be very confusing, and I've read several posts without them fixing my problem. By the way, I'm hosted on Ipowerweb if that makes a difference. Thanks in advance for any direction...