Sure thing. If you want to do a web server ala OSX, then you simply go to the Sharing section under your System Prefs and check personal web server. This will automatically start apache on boot as a service. I think your web site will reside in the ~/Sites directory. You can add on MySQL, PHP and more, but you'll need to look on google for instructions to those. OSX server offers them on install, I believe. I don't know how OSX handles its init process, so I have no clue how to do this in console mode. Someone else should enlighten us both on that process.
Now if you want some hardcore experience by completely customizing your own *nix box. I'd start at
linuxdocs and search for 'web server' or 'apache'. It should give you some of the bare bones instructions on how to get a rudimentary server set up on most any distro. You can further delve into security and optimization settings to completely tailor your server. I suggest linux because it is the only ppc *nix that I have had experience with for web serving, though you can use netbsd or maybe even openbsd to positive effect. I would suggest using
Debian PPC over something like Yellowdog, but it is your choice. Debian also has decent documentation for apache/sql/php/perl/whatever.
Granted the linux/bsd route is going to be very time consuming and involve a lot of initial frustration and confusion if you have no unix experience. It is just something that I throw out to you in case you find alternate OS's interesting, and feel like learning lots of new stuff. You'll also gain an appreciation for OSX's internals and why it is inherently more secure that something like NT (and start really liking terminal.app).
Jim