as far as i know, you creat an ibay for each website you want to host, and then you creat a domain (under configuration) and you get that domain to point to the ibay that you used to host that site, and that should be all you need, if your server is behind a firewall, make sure you forward port 53 udp to the server.
if i got something wrong someone will correct me i'm sure.
and if my explenation is a little unclear just ask and i'll go into more detail.
hope that helps
cheers