You have two options: write one yourself, or use a ready-made one. Writing your own would need knowledge of a server-side language, and would be quite hard anyway, so using a ready-made one is your best bet. I think PH uses WWWBoard (http://www.scriptarchive.com/wwwboard.html). PHPBB (http://phpbb.com) is one of those most popular, or if you don't mind paying you could try a VB (http://www.vbulletin.com/). You'll need to have PHP and some form of SQL installed for PHPBB and VB, WWWBoard runs on Perl.