RSS (Rich Site Summary) is a format for delivering regularly changing web content. Many news-related sites, weblogs and other online publishers syndicate their content as an RSS Feed to whoever wants it.
Why RSS? Benefits and Reasons for using RSS
What do I need to do to read an RSS Feed? RSS Feed Readers and News Aggregators
A variety of RSS Readers are available for different platforms. Some popular feed readers include Amphetadesk (Windows, Linux, Mac), FeedReader (Windows), and NewsGator (Windows - integrates with Outlook). There are also a number of web-based feed readers available. My Yahoo, Bloglines, and Google Reader are popular web-based feed readers.
Once you have your Feed Reader, it is a matter of finding sites that syndicate content and adding their RSS feed to the list of feeds your Feed Reader checks. Many sites display a small icon with the acronyms RSS, XML, or RDF to let you know a feed is available.
History
RSS was first invented by Netscape. They wanted to use an XML format to distribute news, stories and information. Netscape refined the version of rss and then dropped it. Userland Software took control of the specficiation and continued to develop it releasing a newer version. A non-commercial group picked up RSS at the same time and based on their interpretation of the Netscape's original concept of RSS they too released a new version. UserLand was not happy with the non-commercial version and continued development of their own version of RSS (Really Simple Syndication), eventually UserLand released RSS v2.
RSS Links: More information on RSS
RSS Info Comprehensive Overview and LinksSyndic8 - Directory of RSS Feeds
What is RSS, and Why Should You Care?
XML.com: What is RSS?
Introduction to RSS - WebReference.com
