Several things jump out immediately. 1. Can you remove "you are here?" 2. I don't like the rotating "News" banner - it interrupts the flow of reading. 3. Too many clicks to finally get to a message. 4. Color is too bland. Perhaps have a different color for each box of topics to add some visual variety. 5. What is the purpose of the site - is it just for advertising? If so, how will you drive buyers to the site?
the forum is not for only free advertising,but it is for marketing and business discussion and for SEO discussion as well.
Simple and to the point. You should add some more variety of sub-forums to gain a niche market because this site has a very cookie-cutter feel to it. You are also in a satuated market so putting in some niche forums would be a good idea to gain a large returning userbase.