With a shortcode
we can add a site map to your site anywhere we choose. Iyt will self-adjust with additions or deletions.*Here, we are putting it on a page… but it could be a post or a widget as well!
See how to do this at http://en.support.wordpress.com/sitemaps/shortcode/
More on other shortcodes
More on codes in wordpress.com
* Notice how the sitemap is NOT the same as the menu. That’s because we have NOT added the page called “site map” to the menu at this time.
Why do you need/ want a site map?
Because search engines look for it, and having a site map on your site may mean better search engine placement for your site.