I'm working on getting a computer setup that's basically just going to be a local webserver. I know HOW to set the hostname and domain and stuff. but what would I set the FQDN to if it's just a local computer? Do I even need it if it's just going to be a local web server (it's basically just going to have apache and mysql on it)?

i.e. could I get away with just having a hostname called 'mypc' (been working fine in my other machine) or should I do something like 'mypc.foo' or will that mean any reference to web server will have to be http://mypc.foo/ ?

no any name is fine. it's a nice idea to use local domain name, but not essential at all.