What is RSS?
RSS stands for Really Simple Syndication; it is a XML based format for the simple exchange of information. RSS is not used only for weblogs. Many press agencies offer news in the form of RSS feeds and even technical periodicals have the tables of contents of new magazines as RSS feed available. A condensed introduction to RSS can be found here. A rather funny 3.5 minutes video of RSS in Plain English is availbale, too.
Which RSS readers are available?
Currently there are dozens of RSS readers, as this overview shows. For beginners and frequent travellers we recommend a web-based service such as Bloglines.