When you do your dns, you list:
www.mydomain.com hahahahahahahaha> 111.111.111.2 ( your IP address)
mydomain.com hahahahahahahahahahahahahahahaha> 111.111.111.2
if you need more " subdomains " such as news.mydomain.com, you do the same.
Your host should take care of that. If you run your own NS on your box, should be real easy.
Otherwise, use zoneedit.com for your DNS, even as 3rd and 4th just as a safety.
