The writing blog A Book Inside lists 6 essential steps to publishing a non-fiction book. Here are the first three.
1. Planning is the first and most important step. It means asking yourself all the tough questions about the book, from “Why am I uniquely qualified to write this book?” to “Is there a real market for it?” The most effective way to plan is by writing a book proposal, which has a dual purpose: to help you think through the book and to provide you with material you will use later in the process.
2. Writing is the nuts and bolts of producing a book, and it takes blocks of time. This is where all of your planning pays off. The chapters are the heart of the book and, of course, take the most time. They are the reason you are writing — the cake. All the rest is frosting. Begin with Chapter 1, if each chapter is going to build on the one before it, or with your favorite topic, if it doesn’t matter what order you write them. The first chapter you write will help you find your voice, pace, and style. If you submit your proposal to a publisher, the chapter you attach must provide a sample of your best writing and of the caliber of the whole book. In addition to the chapters, you will also have to write the introduction, preface, table of contents, and “back matter.”
3. Professional Assistance comprises all the people who help make a book come to life. You may not need all of them, but consider different kinds of editors, graphic designers, book reviewers, publicists, agents, and attorneys. If you self-publish, you will definitely need a graphic designer. If you prefer a conventional publisher, you will probably need an agent.