RSS stands for Really Simple Syndication. Basically it allows us to "syndicate" information. It's written in the Extended Markup Language (XML), and is used to give special notices to users who don't have time to browse the site for these announcements. Or if we forget to put these announcements in one of the newsletters.
Now, you need a reader. There are several around. One place you may look might be http://www.rss-specifications.com/rss-readers.htm. Another option, some browsers have it built-in, such as Maxthon - an IE-based tricked out browser complete with RSS "Aggregator" (the term for RSS Readers).
Other than that, nothing to it. Now that you know what it is, how to use it, go for it!