It is all pretty easy actually. You need to put all the entries in your DNS, then make a thing called multiple host headers in IIS.
Anyways, this is totally easy.
1. Open the IIS MMC.
2. Right click on the site in question, select properties.
3. On the Web Site tab, look where it says IP Address. There should a button to the left that says "Advanced". Click that button.
4. From here, just click Add and then put in the full name of the web site (ie:
www.me.com).
The IP address is only important if you have multiple IP addresses (multihoming) and different entries for each site in DNS (ie:
www.poop.com points to 192.168.1.1 while
www.asscrack.com points 192.168.1.2 which both happen to be the same machine).
That should be it. Good luck!