Don't feel dumb RangerJoe, Google Reader is a totally different service from GMail (like Google Calendar, Google Docs, etc). Google Buzz was
just added to GMail accounts, so there's also no reason you'd know about that if you haven't signed into GMail for awhile. For your information though...
Google Reader - A web application to handle RSS feeds so that you don't have to check multiple different websites throughout the day. If, for example, you like to get news from CNN, read a few blogs, and listen to a daily podcast, you can subscribe to the RSS feed for each in Google Reader and then do it all from one website. They even just added the ability to monitor changes to websites that don't have an RSS feed (which is not many these days).
Google Buzz - Basically Google's new social network. Closer to Twitter than Facebook, but it has similarities to both. It's also VERY new, so they're making a lot of changes to it right now as people begin to use it. It shows up as just another label in your GMail menu, and when you click on it Buzz is opened in the space you normally see your e-mails. From there, you can share thoughts, links, and pictures. It also connects with many other sites, including Youtube, Flickr, Twitter, Google Reader, and Blogger, so that you can automatically share some things with your Buzz contacts if you wish.