First, there's a LOT of valuable stuff here, basic stuff that helps your website make a better impression with google. Plus google shows you what they see on your site, how often they're crawling it, and all sorts of good stuff.
Secondly, I don't think I've ever seen The Google Webmasters Tools site mentioned on the Warrior Forum before. Even if it was, well, here's another heads up.
BTW, Google explains stuff like robots.txt, sitemaps.xml and a lot of other stuff that gets perhaps a bit mundane, but necessary nevertheless if you just happen to have a website or two in your possession.