[sanjay369]

Here are some suggestions that I have found to work:

Find every relevant link site like http://www.thespaceplace.com/links.html or http://www.assabfn.co.za/spacetides/links.htm and ask for a link, offering a backlink on a separate subdomain will greatly increase your chances

Search social networking sites for like minded people and invite them to your forum

Integrate a wordpress blog into your site using the vbulletin bridge and write articles with pictures and video embedded. Then go and comment on other spaceblogs with your blog URL displayed. Your blog entries will serve as the first-post of a separate article subforum, so if anyone wants to comment on your blog- they are automatically registered on your forum. If you need help with the writing solicit great posters from other forums- with your design skills, they will want to be involved.

good luck and feel free to PM me for community building help- I am sure the size of my community would qualify my advice as valid.