Favorite Writing Books

In my office, I have two shelves of books about writing. One holds books I've read and consider keepers. The other contains books I haven't read yet. (Guess which one is crammed full?) The subject matters range from inspiration to technique to writing exercises.

I've already talked here and here about Julia Cameron's The Artist's Way but some of my other favorites are On Writing by Stephen King (big surprise, I know) and Writing the Breakout Novel  by Donald Maass (which, obviously, I haven't done yet.) I've also got books by Natalie Goldberg and Heather Sellers and Maeve Binchy, to name a few more.

I know, I know - I should spend more time writing than reading about writing but I think having a handful of go-to books is kind of like having your own little private cheering/inspiring/consoling section. So, how about you? What are your favorite books about writing? (Maybe I have some of them on my to-be-read shelf.) What about those books keeps them on your shelf? And what about other writing resources or writing magazines - any favorites there?