This is a useful tool if you want to start a network of readers. If they subscribe to your feed then they will visit your site often for new content. The more subscribers = more visitors = more readers = MORE TRAFFIC TO YOUR BLOG. Make sense??
How do you subscribe or sign up for a feed reader? You can register at http://google.com/reader or you can use RSS OWL. Either way, subscribe to one of them.
Nutang has an RSS address in the modules. Use that module and publish it to your left side or right side module. People can then subscribe to you. You can use your google reader to read the feeds YOU subscribe to.
Another tip.... FEEDBURNER.com will help you burn your feed and get the "spiders" to crawl your page.
Good luck and have fun!