First off, the best way to ensure that a search engine spider finds your site and indexes it well is to use good coding practices. A List Apart's Brandon Olejniczak wrote an article about just this idea, Using XHTML/CSS for an Effective SEO Campaign.
Using meta tags in your page's header is especially helpful because you can define keywords for the search engine to index your site with as well as the description that will be displayed below your webpage's title. Check out the W3School's Meta Element Tutorial.
This Search Engine Forum post, Google Quick Guide explains how the Google search engine works and how to get yourself listed!