Xml-Sitemaps.com lets you create Google sitemaps online through their very easy to use interface. Should be noted that the free service does limit to 500 URLs so going beyond that would require the pro service.

Google Sitemaps helps Google know of all the pages in your website and gives them a single file that adds or updates the URLs in the Google index. All you have to do is sign up for a Webmaster account with Google and then add a website profile and sitemap. This is a must for a site with any kind of depth as you don’t want to rely on the Google Crawler finding all your pages.

Link:
http://www.xml-sitemaps.com/

Check out these posts too:

  1. Google Sitemaps FAQ
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  3. Create webpages through Google
  4. Google now has a URL Shortener
  5. Google improves its Robots.txt tools
  6. Google releases Code Search sitemaps
  7. Webmaster tools from search engines gives valuable information