This hub covers everything between "I think there is a book in this" and "the draft is finished". It is the largest section of the reference, because it is where most books are lost.
The shape of the job
Writing a non-fiction book is mostly not writing. It is a sequence of decisions — about the reader, the promise, the scope and the structure — with a long stretch of drafting in the middle that only goes smoothly if those decisions were made first. Authors who describe the process as agonising are usually describing the experience of making structural decisions at forty thousand words, when they cost twenty times what they cost at four hundred.
Everything in this section is arranged in the order the decisions get more expensive.
Deciding what the book is
What is the first step to writing a book? — The single sentence that defines one reader and one outcome, why an outline written before it is a map of the wrong territory, and three tests to run before drafting a word.
Seven steps to a book that earns its keep — The whole arc on one page: plan, reader, contents, working title, draft, revise, release. Useful as a checklist to see where you actually are.
Building the structure
Writing the first chapter — The chapter-shell method. Build the repeating template every chapter will share, then fill it, and stop treating chapter one as a special case that must be written first or written best.
Building chapters that keep readers reading — Why books are abandoned in the middle rather than at the start, and what chapter length, promise-and-payoff, honest transitions and working summaries do about it.
Titles and headings
Five quick book-title techniques — Five patterns that work at every scale from the cover to the bullet point, plus the distinction between a working title and a final one and four ways to test a title before you commit.
Particular kinds of book
How to write your life story in style — Memoir and family history treated as a selection problem, including the ethical and archival questions that only life-writing raises.
Two things worth knowing before you start
Length is a decision, not an outcome. Decide the target length at the planning stage and treat it as a constraint. A book scoped at 35,000 words gets finished; the same material scoped as "however long it takes" frequently does not. Short non-fiction is a respectable form, not a failure to write a real book.
Your subject knowledge is not the obstacle. Almost everyone attempting a book in their own field knows enough. What is missing is a structure that turns knowledge into a sequence a stranger can follow — which is a separate skill, learnable, and the actual subject of this section.
Where to go next
When the draft exists, move to editing and proofreading and then self-publishing. If you want the audience question addressed in parallel with the writing — which is the right time to address it — see book marketing.
For questions of mechanics, usage and drafting process while you work, Purdue's Online Writing Lab material on the writing process is free and covers the ground properly. The full list of guides here is on the article index.