This may sound like a very silly question, but how could I setup domains ( eg www.foo.com ) on my local network? I know that all a domain is, is just a name registered to a name server and that nameserver has a zone record, and in the zone record there are several records of which the A Record is the most important in dictating where the lookup goes to, which machine it should point to.

I basically want to make it so that I can refer to my other computer/webserver as 'www.foo.com' and make my local sites accessible by that, mess with virtualhost records in Apache and zone records for the domain except locally so I can explore and fiddle around and learn instead of having to rely on the domains I own on a public registrar that I could only access through the internet.

Once again I apologize if this is a silly question, or if I'm completely thinking backwards.

Background information: My OS is Debian, I'm a novice at Linux. I've done very small edits in zone records on a Bind9 Server but that's the extent of my networking experience.