Multiple Sites

Greetings, after days of trying to set up my site I decided to start over with a new hosting service. Installation went 100% better with the new host. Now would like to set up a multi-site configuration. I have been reading some of the posts and have gained some valuable information but I am still confused about how to set it up

I have my domain example.com, and two sub domains example1.example.com and example2.example.com. I have redirected the subdomains to http://example1 and http://example2

Hello

        We can create multiple sites With single db or saperate db for each site.In single db ,

we can define saprate some tables using $db_prefix variable in setting.php.

Read this link for multisite concept http://drupal.org/node/200631