Locking down Linux for use as a web server...

I would like to lock down Linux for use as a web server, where do I begin? What exactly am I disabling/blocking? I guess I can do a port scan, but does that check if I really have successfully locked down Linux? If I were to format and install with only the minimal programs needed (Apache, PHP and firewall,) would that help in any way?

I suppose I'd start by closing all unnecessary ports. You'll probably need to keep port 80 open, plus any other ports you need for the internet (443, 22, etc)

Via firewall? Uninstalling software? something else?

research firewalls and ftp daemons. make sure that ports 80 and 21 are open as a minimum. you'll need another port open for a control panel tho this can vary!

The best practice is to have just a plain command line version.... no GUI, no graphics, just pure coding!

You mean don't install KDE, GNome and the rest, or just to run apache, PHP, etc. from command line without starting xwindows? Anyone know of a command line controlled firewall? Would I be better off with a hardware firewall for the entire network instead?