Forums are one of my favorite methods on social networking. I get to meet great people, pick up tips, share ideas and advertise my business. If you are new to forums you should no that you don't want to post the link to your website or place blatant ads. What you want to do, is join in on some of the discussions and get to know people. Most forums give you an option to add a signature link. This signature will do the advertising for you. So if you write good content, people will often click the link in your profile.
I wanted to invite you to join one of the MLM forums that I moderate. Work From Home Board is a great place to meet other net-workers. I have several forums that I belong to. This one is a smaller group and has some really nice people. By the way, your signature doesn't appear until you do 25 posts.