the most popular forums (meaning the ones i've seen used the most) are phpbb and vbulletin (which this one is). they both run on php, so if you use either you'll need that. i don't know how suitable either forum is for advertising so maybe you'll need to check that out (by that i mean - i don't know how search engine friendly they are). i've always used dreamweaver for any sites i've done and never had any problems with layouts. i tend to use tables for the layout but i know some people like using divs (layers). i don't like layers because you have to set different positions for dofferent browsers, which just makes more work for yourself.