Now that Google has redone their ranking algorithms there are some things to keep in mind relative to the old reciprocal links game.  Namely it is important that you not add too many of these kinds of links too quickly, build them up gradually otherwise you will be identified by the search engines, as it will be seen as unnatural.  If this happens than you might see your rankings in the search engines disappear instead of rising. A good way to start is keep the number of new links to less than 10 in one month.

For years Search Engine Optimization (SEO) has been characterized by the effort to trick the seach engines with shadow networks or the more benign practice of trading links.  Google has implemented a new system called Jagger that now finally makes all this futile.  We have finally arrived at the age where the ranking of a site will be based on that site's content and the quality of that content.  If you want to get a high rank, start doing the real things that should improve your rank, namely publish relevant content, write articles with links back to your site, actually participate in online discussions about the topics you wish to be well ranked for...

This is actually good news (as you should be able to tell by my tone) since we are finally beyond the "get rich quick" mania that has been the mainstay of SEO since it's inception years ago during the Dot Com boom.

Write and encourage your community to write in your forums.  Do the things that will make your site worth visiting and the traffic will come.  A long hard road, but a fair one.

A key part to the success of any website is content.  If you are basing the business on traffic then the more content the better.  You can write that content yourself, buy it or you can design a site that causes your users to provide the content for you.

You have likely visited many sites yourself where you are welcome to share and contribute.  Each time someone does, whether it is to vent, rant or console, the site benefits by the addition of more content.  A big factor in all search engine ranking is the number of pages in the site.  If you can leverage the work of others, it can make the difference between having dozens of pages (or hundreds if you are prolific) and having thousands of pages.

Ultimately unless it is completely out of place, think about putting forums on your site.  It is the best way to get contributions without having to invent a new paradigm.  If you are hosting on a dedicated server then you likely have to find the software yourself, but on most shared hosting providers there is already software in place for you to leverage.