What is RSS?
RSS stands for Really Simple Syndication. This technology uses XML and allows a user to "subscribe" to websites that have provided RSS feeds. Feeds typically are provided on web content that changes regularly. RSS is widely used by weblog and news organizations.
How do I use RSS?
In order to subscribe to and read an RSS feed, you must have an RSS reader (sometimes called a news aggregator). These programs can check the feeds that you've subscribed to and present to you updates of these web pages in a summary format, allowing you to click on links to read more about an item on the feed. Once you have a news reader, you can then enter the URL that the website has offered for the feed. This is typically accomplished by clicking an orange box with the words RSS or XML on it and then copying the link to the subscription box of the news reader.
Where do I get an RSS reader (news aggregator)?
There are many different ways to subscribe and receive RSS feeds. Many web browsers and email clients either offer native RSS capabilities or have a plug-in that you can install. There are also many applications written (many of them free) that are available on the Internet.
There are also many online news aggregators that allow you to view your rss subscriptions from any computer (via the web) and offer other services as well.
A good list of available RSS readers (and links to online aggregators) can be found here: http://en.wikipedia.org/wiki/List_of_news_aggregators at the Wikipedia web site.
More information about RSS can be found at: http://www.wikipedia.org and searching for RSS (in the language of your choice).