Nonfiction writers don't write the book first and then sell it like novelists. They create a book proposal and offer that to publishers instead. The book is written after they have signed the contract on the dotted line. One important piece of the nonfiction book proposal is the outline. Hence, nonfiction writers must strive to create succinct and professional outlines to help them land publishing deals.
Some writers want to self-publish and feel that an outline isn't important for them. You might want to rethink this. The best books are well organized, and the most powerful organizational tool of any author is the outline. All nonfiction writers should consider developing an outline for their books. There is nothing worse than a great idea that is poorly executed. It's a missed opportunity.
What's included in a nonfiction outline? Your outline must be a clear plan that will guide you as you write your book. It will help you keep on task and hold your vision. Think about it like it is a blueprint. Very few people build a house without a blueprint. If they did, we would all live in ramshackle huts. Books are complex structures too. Your outline contains the entire structure that your book will be built upon. An outline will help you organize your ideas. It will help you pick out your most important ideas, group those ideas, and subordinate and coordinate them appropriately. A well organized book will showcase your non-fiction material.
In terms of the physical form of your outline, you should have an ordered list of chapters with brief descriptions of what each chapter covers. Each short description should focus on the core idea of the chapter with great clarity. There should be no extraneous fluff like droning descriptions of supporting material or tangential information that moves away from the core purpose of the book. How many chapters should you include? You need to do your research and find out the standard length of similar books. You may envision 100 chapters, but if all similar books have 21 chapters, you will winnow your material down to the essential, or you may realize you have more than one book to write. Don't forget to investigate the length of chapters in competitive books. Do you need long chapters or short ones? This decision will help you as you organize material.
A helpful resource for writers is the Purdue OWL, a free online writing lab. It's a great site to brush up on the ins and outs of developing an outline. Some writers turn to writing software like Scrivner and Inspiration to help them create professional outlines. You might also want to check out How to Write a Book Proposal by Michael Larsen, who co-founded Michael Larsen-Elizabeth Pomada Literary Agents. Develop a clear plan for your book, decide how long and how many chapters you will need and write short concise descriptions of each chapter. Your outline will help you make your book breakout.