There are a lot of SEO (search engine optimization) people out there willing to sell you all sorts of solutions to search engine ranking, but a lot of those solutions are of dubious value, or even worse may hurt your ranking.
The most important thing by far is links to your site from external, quality (i.e.: well ranked) sites. Also important is the content of your site, properly marked up in valid, semantic HTML such that the search engines can interpret the content and give appropriate weight to the various terms and phrases used within it. The two work together, as links to your site are no good if the search engine does not know what your site is about, and knowing what it is about is no use if no one links to it.
Anything else you read about for SEO is, at best, icing on the cake that might help a little, but very little compared to these two main concerns. And beware of "tricks" like overloading a keywords meta tag, submitting your site to "link farms", etc. that might actually hurt your ranking.
