Can't get Multi-Domain options to show

I installed the Multi-Domains plugin and see a few options, but I can't get any options to show on a page for members who will be using the the multi-domain function.

Please let me know how I can do the following:

1. Under the options it says: "Change the DNS records for each domain to point to this WordPress installation." When I go to change it, am I putting the server info or something else? I have 3 addition sites and I'm pointing the domain to the server, but can't get the webpages to pull up.

2. How can I make it so my members can go to a page and pick their own sub-domain and start using it?

Thank you!