WebMonkey has an informative RSS tutorial:

What is it really for, anyway? Two things: RSS (Really Simple Syndication) is an easy way for sites to share headlines and stories so that other sites can integrate them into their pages. Additionally, some savvy surfers use special RSS aggregators %u2014 kind of like mini-browsers %u2014 to speedily flip through the latest news and links from dozens of sites.

It includes information on what RSS is, how to get an RSS feed, and what to do with it once you have it.

...via Scripting News