Writing books are an interesting niche market. Writers, by their nature, are readers and reading about writing seems really close to actually writing itself--after all, we're working on improving our craft, right?
Yes and no.
Yes--books on writing teach us different ways to approach this writing gig. After all, it's easy to say "Just Write." It's like a Nike slogan. "Just Do It." But the actual writing can sometimes be difficult. You run into snags with characters. Sometimes you just don't have the ability to build tension the way that you want to. Then there are those moments where you think that you're the only one who has had these struggles.
For direct problems like these, writing books can show you how other authors have pulled off those pesky character/plot problems. Books on grammar can show you how to construct a sentence if there's something wonky in your structure. Plus, there's loads of encouragement out there for writers who think that they're all alone, and Stephen King's On Writing and Anne Lamott's Bird by Bird are probably two of the top books for that: both grant permission to fuck up and experiment while telling you to learn the basics.
No--There are other books out there that are not as useful, and I would argue can even be damaging. Generally speaking, if there is some sort of graph, plus worksheets, plus a 'plan to get you to write your book in 24 hours', I think that you can safely burn these and not lose anything. Any book that tells you there is just one way to write a book was probably written by someone who has only written 'writing' books.
Good writing does have its rules, but following strict guidlines, with no flexibility, is like trying to follow a diet to the T right off the bat--it generally doesn't happen and all you're left with is a bunch of fat-free, wordless pages and frustration.
I would also make the observation that sometimes writers think reading writing books equals writing. This is just not so. If you're looking for inspiration, fine. If you're looking for a piece to the puzzle of the story you're working on, fine. But all of these writing books should only be read in conjunction with writing. Always, always be working on a piece of writing while you read the books on writing. That's the only way they'll actually be able to help you. It's the way they're designed to work.
What writing books have you read that were useful? Have you come across any that you thought were damaging or just written by writers wanting to write about writing? (Say that three times really fast!)