http://en.wikipedia.org/wiki/Really_Simple_Syndication
Introduction to Feed RSS.

http://www.xml.com/pub/a/2002/12/18/dive-into-xml.html
Tutorial about Feed RSS, including history of releases and examples

http://www.xul.fr/en-xml-rss.html
RSS tutorial including how to build and use a feed, step by step.

http://allrss.com/rssreaders.html
RSS Compendium.

http://www.mnot.net/rss/tutorial/
RSS tutorial.

http://www.rss-specifications.com/
A comprehensive RSS reference

RSS Specification

http://blogs.law.harvard.edu/tech/rss
RSS 2.0 Specification

http://www.rssboard.org/rss-specification
RSS 2.0 Official Specification

http://backend.userland.com/rss092
RSS 0.92 Specification

http://web.resource.org/rss/1.0/
RDF Site Summary (RSS) 1.0 Specification

Feed RSS for News

http://www.cnn.com/services/rss/
CNN's RSS (Really Simple Syndication) feeds to get news

http://today.reuters.com/rss/newsrss.aspx
Reuters's news RSS service.