One of the least technical, but most time consuming, things you can do to increase your search engine rankings is to work on increasing backwards, or incoming, links. Links to your site from other sites.
The best way to do this is to scope out your competition. Using Google search for your keywords and, check out the backlinks of the top ranked sites (enter "link:http://www.thesite.com") into Google's search box. Your goal should be to get every page that links to them to link to you. You can also try this link search on other search engines to make sure you're getting the complete list. Once you have the list you can submit to the places that accept submissions and email webmasters if they are link pages.
Another method of finding places to submit your site is to search for "your keywords" and "add url" or "submit url" or "add site" or "submit site." This will locate all the small niche directories or automated link pages that you can submit to. Make sure you try a couple keyword variations too.
You can spend days or weeks working on link popularity by doing the above things, there is no such thing as spending too much time on it. Once you've done it though its like a gift that keeps on giving. Those links will stay up for a long time, if not forever, your traffic will increase, and as your traffic increases people will add links to your site on their own.