When you’re working with a limited budget and need to increase your visibility with minimal expense, then forums are a great place to start. The effect of posting information and opinions on forums are two-fold:
When you post to forums you are posting information to a targeted readership that is interested in the forum topic. Provided that you have chosen a forum related to the topic of your website you are, in posting interesting and insightful information, promoting your own knowledge of the area and people are likely to visit your website based on this.
An additional benefit to forum posting is that you will generally have the opportunity to add your website address to your signature. This acts as a beneficial link to your website given that it is from an entirely related site. This will count as a quality link to your website and help to improve your link popularity on the search engines.
While forum posting can be a time consuming process, especially in the beginning while you are having to set up accounts, create your profile, etc. it is one of the best of the zero cost (other than time) marketing tactics.
To find forums related to your topic you can visit one of the major search engines and enter your keyword along with the word “forum”. This should give you a good list to start from though in your travels you may find other quality forums to post to.