There are about a zillion books out there containing writing about writing.
There seems to be an entire subgenre of the Self Help world devoted particularly to helping you become the writer (or artist of any kind) that you're meant to be. I've read a few of these and find them to be a mixed bag.
There seems to be a spectrum of focus in these books. At one end you have the nuts-and-bolts practical guides to writing, including style guides, do's-and-don'ts lists, and advice on navigating the more business-oriented aspects of trying to get published. At the other end are the cheerleaders of self-expression books, the ones that give you permission to really be you and exhort you to put yourself out there and give you idea prompts for taking yourself on self-indulgent little jaunts to find your creativity or whatever.
Wherever a book falls on this spectrum, there is usually some element of memoir involved where the writer of the book shares his or her experience of becoming a writer. This, too, can be helpful and relatable or totally solipsistic and pretty useless. There's the kind where authors shares their very particular way of going about things that works for them and might work for you, too. And then there's the kind where the authors describe all of their neuroses so you know how very special they are and how you, too, can be a super special important person if you cultivate your own stable of hang-ups and self-limiting problems.
But when I do come across some writing on writing that clicks with me, it can be very inspiring. There are writers out there whom I admire and who I think have real wisdom to share. Lately I read On Writing: A Memoir of the Craft by Stephen King and found it to be a perfect mix of all the things that a writer needs to read about. For my money, this book is in the ideal range of the spectra I described above. (You can read my Goodreads review by clicking on the link in the title.)
Since reading it a couple weeks ago, I have been sitting down to write every day. I've started work again on that fantasy novel I've been writing in fits and starts for a couple of years now and have a renewed sense of purpose and confidence with telling the story. I have also gotten sidetracked from working on that because fiction (and world-building fantasy in particular) is a lot of work and sometimes it's easier to write blog posts about doing things I love, like this one. And that other one about horses. And an another one that I'm kicking around ideas for in my head lately.
It's a hell of a lot easier to write about writing than it is to just write. Getting sucked into writing about it--or reading about it--too much can give you the false sense that you're getting the work done when you're really not. The only thing that can truly help you write is to sit down and write. But sometimes the encouraging words of someone who knows the joys and pains of the work that you do can be helpful to get you started. If you're looking for that, I highly recommend Mr. King's book. You can also click here for a list of some other books I've read on the topic and my reviews for them on Goodreads.