I finally got around to reading through David Gaughran's blog--it's very news oriented, so many of the posts date quickly, but he's got a very detailed post of a promotion he did that had a lot of good tips (as do his other posts on promotion). But my favorite is a guest post about how Mainak Dhar learned everything he needed to know about self-publishing in seventh grade.
And I also liked this post by April Hamilton on the unpredictability of success. I do think that there is something of a formula for success, but it's certainly not as simple as Push Button A, Get Result B.