I'm on about 8 forums that are all targeted to my niche. 4 are fairly active and 4 are not so active. Three of the active ones are my biggest sources of traffic next to google and yahoo answers.
I always try to leave extremely helpful answers that leave people with the feeling that I'm an expert on my subject. I link to RELEVANT pages on my website in the body of my posts. That got me in trouble with 2 of the non active forums, but on the active ones, everyone loved it. When I open up a new section of my site I will actually post, hey guys, I have some new info for you on this subject. And everyone says, "Oh thanks!", etc. I can do that because I have great content. I also post other helpful info that doesn't involve my site.
One thing with active forums, you have to post quite a bit up front to get people to recognize your user name. Have a personality and don't be afraid to go against the grain on certain subjects as long as you know what you are talking about. I am not only living the topic of my website, I have researched it thoroughly by checking out dozens and dozens of books from the library. Other forum participants pick up on that and actually look for my posts. Some e-mail me privately for info.
At one point I was getting practically ZERO traffic from google, and Yahoo Answers and Forums were my only sources of traffic. With those 2 places alone, I was earning a google check every other month and making a few affiliate sales.
You have to build credibility though, and not just pop in to try to sell something. I stayed on both forums I got in trouble at, and both moderators eventually apologized and thanked me for staying around!
Another thing I do on forums is change my siggy now and then. When I open a new section of my website, I may change my siggy to promote that. For example when I built a new Tier 2 page on affordable homeschooling, I changed my siggy to say - "Check out these tips for Affordable Homeschooling!" With the text linking to that page on my website.
When I have a newsletter coming out, I change my siggy to promote it. For example "Looking for ideas for Valentine's Day activities, sign up for my homeschool newsletter!"
My sign ups doubled every month I did that and my ad income also spiked. I don't have an ezine list in the thousands or anything, but my site is still new and in the 100's is better than nothing.
