sitemaps.org - great resource about sitemaps
OK, so while working on a project to build a multi-thousand page series of sitemaps for our properties here at work, I found this resource: http://www.sitemaps.org/
The site is good at one thing,and one thing only - sharing information about sitemaps. Many folks today see them as a sort of Holy Grail. A way to magically improve search rankings, and it’s easy to see why.
A sitemap page helps your internal link architecture by adding a series of internal-facing links. It can help boost… page views if properly placed and sued by readers of a site. More links to explore means more likelihood of something interesting catching their eye. Finally, increases in inbound search traffic often result from a sitemap being included on a site.
Is it the sitemap that boosted the rankings?
Hardly.
All the sitemap did was provide a path for the spiders to find pages they previously couldn’t access. Sure, that fancy Javascript navigation sure is cool. but it’s also keeping spiders form finding and indexing all your pages. In such a case, the increased search traffic came form simply allowing the pages to be indexed. The pages themselves did the rest.
So, yeah, sitemaps are important. Are they the silver bullet? Nope.
Search rankings are a game of inches, not miles. 
