Like D. Keith Robinson, I've spent a lot of time lately trying to explain feeds to people. I've said before that I think feeds are the element of new web technology that will change people's use of the internet more than any other.
Keith wrote Fixing (RSS/Atom) Newsfeed Subscription about how difficult syndication and subscription can be to explain to someone who doesn't understand blogs, aggregators and all the pieces that are central to the new web.
He recounts his conversations and struggles, and links to a study by Catalyst Group on the usability of blogs, which studied the reaction of experienced web surfers to a Business Week blog that was created as part of their web site. The users didn't understand that they were on a blog and were unclear on the functioning of many aspects of blogs that regular readers or posters take for granted, such as comments, trackbacks and categories.
Keith also provides some links to good explanations of how feeds and subscriptions work and articles about subscription usability. I'm beginning to collect descriptions of how to subscribe and how readers and feeds work. I plan to read all of them and list the best ones I can find, sometime in the (hopefully) near future. So if you've written or found an explanation that does a good job with the basics of feeds and readers, please leave it in the comments.
Update: It occured to me that this is a good use of del.icio.us, so I've created a tag "subscribetowebsites" and tagged all the sites I've found so far.
There's no evaluation or quality check, just anything I've come across in the last week or so introducing feeds and readers.