If you want to do that, get mySQL and PHP and install them on your iBook. I recommend the installer from serverlogistics, but there are a number of ways to get them going on your computer.
Then get a recent copy of the phpBB installer and set it up in your sites folder.
You'll have to get your head around creating databases and users and the install process. You can find out about skinning it and other customizations.
Then when you get hosting the proper hosting and push a button - you'll know what's going on.