I thought I'd mention the Electric Speed newsletter. Published a couple of times a month by Jane Friedman, who used to be an editor at Writer's Digest, it always includes some useful information.
For example, a few months ago it gave readers the heads-up abut a free book on book marketing, and it often features a useful tool or two for writers.
It's definitely worth checking out. The newsletter page is here, and in that you'll find a link to the Electric Speed newsletter archives.
On the subject of newsletters, I hope to launch the first issue of Reviews for Writers soon. If you wish to sign up for that, just click that link.
I'm currently re-reading Jane's book, Publishing 101, and will be writing a review of that soon (along with a review of Michael Hyatt's Platform). I've already written a very quick review of it, but I want to write a more in-depth one. The link to that is: Quick look: Publishing 101.
And while we're on the subject of books, you may find my review of The Content Code useful. I've implemented a few of the author's suggestions, and have seen good results. I suppose it may all be part of what Matthew Syed calls the Placebo Effect in Bounce, but hopefully not!