a lot of forum see in footer they have vbseo, but that is not vbb forum right? What is it exactly please and do i need to buy it with vbulletin????.....

What is it exactly please and do i need to buy it with vbulletin????.....vbSEO is an add-on application, that runs with vBulletin. It puports to make the forum mor search-engine friendly (SEO stands for "search engine optimization"). You do not need it to run a forum. It costs money to buy. I have no basis to judge whether or not it helps with search engine placement.

Hello. What is the best way to promote vBulletin board?

Put you site URL in your signature when posting on BB sites "If permitted"
Try and get link exchanges with other sites "if you get lucky, you can get your site linked on a high ranking sites"
Submit your site too ALL major search engines "Google, Yahoo, MSN, Live.com, etc"
Also search the forums for SEO (http://www.vbulletin-fans.com/search.php?searchid=6019)