Finding Feeds

Library training is entrenched! I found that I automatically liked some sites because of their layout (eg. reading from left to right), or the types of subject categories.

Feedster - I spent some time trying to find exactly what I wanted, but eventually succumbed to other search tools.
Topix.net - surprisingly I discovered I liked the "All Topics" listing, scrolled down to "Health and ADHD", then searched on "Oranges". I found 3 useful updates. Maybe it helps to be interested in a very specific subject - you can find your way through the maze more easily.
Syndic8.com - I found this difficult to get used to the layout, but suspect there's some really useful stuff here.
Technorati - now suddenly this layout felt "comfortable"!

Nevertheless I still haven't discovered the search style that suits me best, so am still taking a while discovering what I really want. I thought the 100 Top Blogs was useful eg. discovered Read/Write Web (growing network of blogs about web technology).

RSS & newsreaders

Well, the world's our oyster ... or maybe not.
So much information can be found, but how to put in enough practice to ensure you find useful links quickly?
I think this would be quite useful for liaison librarians if targeted at quite specific content specialisation for teachers eg. find feeds that target advocacy for children, updates on sites selling support materials, etc.

How do you keep these "up to date"? It's relatively easy to run a web checker through specific links to detect URLs that are "broken", no longer link, etc. But short of putting in the hard slog, how do you detect when posts, feeds, etc, are no longer relevant?