Craig Berntson already gave you some great answers. If you get yourself a news aggregator and then subscribe to the feeds that interest you, I think you'll have a better idea of how it works from a reader's perspective. News aggregators are the means by which all of the content that interests you is brought together in one place and it will inform you when new content is available in for any of the feeds you are interested in.

How to find the blogs that might interest you? Well, you can start by looking at the blog rolls (a list of links to other blogs/feeds) that you will find on most blogs. If someone, who's blog you are reading, appears to have similar interests to your own, then there is a high likelihood that the blog roll will contain some blogs that you will find useful.

There are also search engines devoted to feeds, so just as you use a regular search engine you could use one of the following to find feeds that might be of interest to you.

http://www.feedster.com/
http://bloglines.com/
http://www.technorati.com/