I was just telling a friend how important this book is in highlighting the nuts and bolts of writing in that it's a lot like building stuff. We tend to romanticize the writer as having ideas come to them with hot cocoa and a NYT bestseller literally pouring from their fingertips, but the reality is a lot closer to grinding at an especially punishing task. Mr. King highlights it wonderfully, and even if you're not a fan of his work (huh?), I highly recommend you read it.
It also contains a chapter he wrote pre-edit, then post-edit, and why things were kept, reduced, taken out, etc. One of the most helpful things I've seen from a professional writer.
Thirded to the above, and I'd humbly add Orwell's seminal 1946 essay "Politics and the English Language."[1]