The creation of site maps in Typo3 is pretty straight forward. You can either use the built-in site-map function or the extension fl_seo_sitemap. The later has the advantage of being adjustable using CSS.
Have a look at an example for an human readable site map created using the SEO plugin.
For the automatic creation of a site map for Google in XML format, there exists another nice extension mc_googlesitemap. It provides not only functions to create site maps for the individual pages of the Typo3 CMS but also for database content such as news items. At our system, the site maps for content items did not like to work at first. A look at the source code showed the problem. We did not have the news items assigned to a news category. After doing so, the site map worked.
Here are examples for a Google site map for pages and a Google site map for content items.