The Mindful Writer

By Dinty W. Moore

Every writer needs this book. We all feel lonely, uninspired, and discouraged sometimes—it's just a part of this crazy profession. The Mindful Writer is for those low moments. This little book is filled with the wisdom of many writers, plus Moore's practical and inspiring commentary. I revisit it when I'm looking for a nugget of wisdom, mindfulness, and joy. When you feel overwhelmed, imperfect, or bogged down in details, pick up this book and remind yourself that you write because you love to write—which is the most important thing to remember, anyway. 

Note: You can get this book used at a low cost, but I believe Moore is coming out with a new version soon. 

The Writer's Portable Mentor

By Priscilla Long

If you want to take your writing to the next level, this book is for you. Primarily written for short fiction, this helpful guide is easily applicable to novel-writing as well. Long covers everything related to the art and craft of line-by-line writing: word choice, fragments, sentences, paragraphs, etc. This book will naturally appeal to literary writers, but I highly recommend it to any writer who wants to use their language more fully, functionally, and beautifully. 

Characters and Viewpoint

By Orson Scott Card

This is one of the first craft books I ever read, and I still revisit it. Card offers practical, straightforward advice on how authors can select the right viewpoint for their story and master character development. Highly recommended for beginning writers who are just learning the ropes, and intermediate writers needing to brush up on their skills.

Another great book by Card is How to Write Science Fiction and Fantasy—if you're writing in those genres, I suggest you pick that up, too. 

Deepening Fiction

By Sarah Stone and Ron Nyren

If you're thinking about getting an MFA in Creative Writing, I highly recommend you explore this book. I read it for one of my "craft of fiction" courses and was blown away. You'll be surprised by this book's depth in describing the hidden nuances of craft elements you've already studied. Prepare to learn techniques you didn't know existed—this book captures and describes new ideas in straightforward, useful terms, empowering and encouraging experienced writers to take new leaps within their work. 

The Theory of the Novel

Edited by Philip Stevick

This book is not for the casual writer, but if you're serious about understanding craft, it's a wonderful tool. These essays offer the advanced writer an in-depth look at how the novel has evolved over the years, both from the viewpoint of the critic and the author. Some essays will feel dated, but if you genuinely love to explore the history and evolution of the craft of writing, you definitely need to pick up a copy.