Keyword research is one of the most important things you can do for FREE to optimize your website for search engines to find your business.
First, you must decide on which keywords you want to define your particular business. Deciding on keywords will help you determine which copy you should use for your website and how dense your keywords have to be site wide in order to get the results you want.
Second, you must submit a sitemap to search engines so they can see which pages you want to be visible. Search engines like Google, MSN, and Yahoo crawl your site for pertinent information to compute how relevant your site it against other sites with similar keywords.
Third, you must write and submit articles and press releases that will point back to your site with those relevant keywords included in your text. There are many sites that will tell you how many times you mention a particular keyword in your copy and I encourage you to use those services.