the easiest say is to use either kde or gnome: go into your system menu and choose apache.
within apache you can add new "virtual servers" .. make sure you add a "name" server .. then you just type your ip and domain name, and what directory you want that traffic to go to.
you have to make sure the company you registered with is pointint to your ip.
i am assuming you have a static ip.. i just set mine up so i've been through it all this last week. if you need more help, just make your question more specific.
good luck,
-mike
