Don't know exactly how involved you want to get into a forum, but the forum/message boards that were mentioned before require you to pay for a hosting service AND said hosting service would have to allow you to install and/or upload server-side applications & scripts to operate. This could end up costing you alot - especially if you're already paying for internet access either through AOL or a broadband service like DSL or Cable (if you're using one of these services, you're already paying alot, why pay more?)
Anyway, if you're just looking for an easy to use/no-brainer board, try one of the free boards offered online. I use ProBoards myself (
http://www.proboards.com). It's not too bad. You do have to put up with a banner ad across the top of it, but you can pretty much control just about everything with the setup. You can make it so that people can't post unless they "join" the board (to control those "guests" that like to post advertising on open forums). It also gives you a subdomain off of their domain (i.e.- YOUR-NAME.proboards.com).
This way, they host it and have all the tools you need to run & maintain the forum and it won't cost you a dime.
Although, one bit of advice: be cautious of HyperBoards.com - it's a free message board service like ProBoards.com, but I had problems with them in the past. The advertisers they allowed on their system were pushing spyware and trojans down on users who accessed the board so I quit their service.
I haven't had any incidents of that with ProBoards.com, but you should always keep an eye on your system anyway. Many websites today have advertising that will push down Spyware applications & keyloggers. Make sure that, whatever route you take, your anti-virus software is up to date AND that you have a spyware protection/detection application or two on your system ("AdAware" & "Spybot Search & Destroy" are two highly-recommended anti-spyware applications available free on the Net - search for them on
www.download.com)