Domain mapping for beginners

There are four pages of posts on domain mapping and I find none very clear.

I installed the plugin as directed. The sunrise commenting is removed (edit the wp-config file to remove the two slashes in front of the comment that has the word sunrise).

I have shared hosting at hostgator and there is a "dedicated IP address" on the side bar.

I put that address in under site admin options. I then added an A record. Hostgator asks for a "name" and I put in the folder name for the blog (blush), and then the dedicated IP addy under "address".

I put in the domain name I wanted the subdirectory domain to point in the admin panel under tools.

I did this for two domains. Each time when I click on the link in the admin panel I'm directed to the domain on the web, not the wpmu installation.

On one of the domains, I had the bright idea to test those three options in site admin for the admin panel and I'm now unable to access that site's the admin panel.

I really need for this plugin to work.