Nice interview with John Gruber, proprietor of Daring Fireball. His explanation of how he selects links could easily double for mine:
As for what I link to and what I don't, it's very much like Justice Stewart's definition of obscenity: "I know it when I see it." There's a certain pace and rhythm to what I'm going for, a mix of the technical, the artful, the thoughtful, and the absurd. In the same way that I strive to achieve a certain voice in my prose, as a writer, I strive for a certain voice with regard to what I link to. No single item I post to the Linked List is all that important. It's the mix, the gestalt of an entire day's worth taken together, that matters to me.