Heard about Google’s new sitemap program?
On June 2, 2005, Google announced the beta of their new service, Google Sitemaps. This provides Webmasters with a method to map site URLs into an XML based format. On some regular interval, Google will read the sitemap .xml file, to better understand the exact content of the site, and what has been recently updated on the site.
Basically, you generate a sitemap in the correct format using, and the update your sitemap when you make changes to your site. The sitemap.xml file you submit to Google must adhere to certain guidelines that Google has established. This “set of rules” is provided in the format of an .XSD file (XML Shema Definition) on the Google site: Google Sitemaps .XSD. Once the sitemap .xml file is built, copy (or FTP) it to your Web server, then go to http://www.google.com/webmasters/sitemaps/ to submit your sitemap to Google.