I gather ideas for this blog from a wide range of sources, but these are my favourites:

Wikipedia
You may have heard of this one already?

Metafilter
Just the best darned community-collated collection of links and commentary this side of the black stump.

Futility Closet
The finest one-person blog on general trivia out there.

No Such Thing as a Fish
A podcast by the researchers behind the TV show QI. Endlessly amusing.

In Our Time
A long-running British radio programme (and now also a podcast) by the grandfatherly Melvyn Bragg.

Brewer’s Dictionary of Phrase and Fable
One of the best reference works for the professional browser.