There seem to be several theories as to what RSS stands for so I will go with the most popular, Real Simple Syndication.
OK, enough geek speak, you want to know what it can do for you, right?
I imagine your car radio has several stations programmed in. These will be the stations that best fit your tastes. There may be a few featuring your favourite music and perhaps a traffic report station. Having them programmed into your radio means you can access them with one push of the button instead of searching everytime you want to tune in.
RSS can do the same for your web browsing. Rather than opening endless emails or trawling through websites hoping to find a nugget of useful information you can subscribe to RSS feeds from the people that have something interesting to say.
Your RSS reader will give you a headline and perhaps a line or two from the latest update and you can then decide whether to read on or not in much the same way as you scan the headlines in a newspaper until you see a story of interest.
There are RSS feeds available on just about every topic you can imagine. Whether you want to keep up on world news or the latest trivia you will find many feeds of interest. If your tastes change or the quality of the content drops off then you can just delete the RSS feed from your reader. No more opting out of email lists, putting up with 'follow up' autoresponder messages, just instant on/off access to information that deserves your attention.
This has to be good news as with the rise in popularity of RSS feeds the publishers of feeds have to stay on top of their game. They know that it is very easy for you to wander off elsewhere. You wouldn't continue to buy a newspaper or a magazine that bores you would you? This means that the quality of a feed is generally vey high which is certainly a positive step in the development of the internet.
Finding feeds is very easy - when you find a site or blog that you like just look for an XML or RSS button, usually orange or blue. If you click the button however the page you are taken to is just a bunch of HTML so you need a RSS reader to make sense of it. Just take a note of the url in the browser window at the top of your screen.
If you are a Yahoo subscriber you can simply add the url of the feed into your My Yahoo page. Google also now offers this service through Google Reader. Some browsers, such as Firefox also have RSS readers built in (just choose the add live feed option in the bookmark manager). Other services such as Quikonnex also offer a messaging service too which means you can completely bypass the whole spam ridden, over filtered ISP email system.
With RSS feeds available from broad subjects to narrow niche topics the internet now provides what it was originally supposed to do - share the best quality, most relevant information immediately.