Do-It-Yourself Search Engine Optimization
PART III: OFF-PAGE FACTORS
Once you have selected your keyphrases and optimized your pages for them, the last step is to make sure that you get linked from the best directories, and from lots of quality sites with a topic related to your site's.
The best search engines, and in
particular Google (who alone can deliver 80% of the search engine
traffic to your site) "crawl" the web looking