Idiots guide to setting up bulletin board / discussion area

[#1]

anyone know of anything that would allow me to set it up for one of the domains hosted in my webspace?
it needs to be free!
Thanks
PT

[#2]

The forum software used for this Community is called Simple Machine Forum (SMF), and it's free.
The installation instructions are here.
I'd suggest you read through those and, if it seems like what you are looking for, then ask again here for someone to explain any mysterious points.
This Google search shows lots of places that also use the SMF forum software.