Actually, if you would just like a ready-made message board, you could install phpBB in CPanel under the Bulletin Boards icon. You would then get a board that is the same as this one (of course it is the default template and you would have to make changes to it). We have a whole slew of previous forum threads about phpBB and you could find about them by selecting search and searching for them here. Thus, if you decide to go with phpBB itself, you wouldn't need to use dreamweaver to make it.
Next, I would suggest learning about making an html form by visiting www.w3schools.com
and going through the html tutorial which includes forms there. As for the script to process the form, we only recommend one and it is TFmail at NMS scripts:http://nms-cgi.sourceforge.net/scripts.shtml
We have a how-to on the forum in the How-to section with instructions on getting it to work with your form. If you have any questions on getting it to work, just PM StevenP (he did the tutorial).
I hope this helps.