Building a sitemap

Is there any tutorial or extension which helps me building a sitemap map for a larger web project easily? I prefer to use Dreamweaver MX only, no external programs.

If there is a tutorial/extension, where do I find it? Is it free?

A possible extension should contain an easy to use surface which allows to introduce the categories first. In a next step, the extension should allow to insert the subcategories and/or links that belong to the main category. The result should be an html page.