[header] How to write a nonfiction book [title] Understand the genre. [step] Nonfiction writing is literature based on fact. Nonfiction writers can focus on topics like biography, business, cooking, health and fitness, pets, crafts, home decorating, travel, religions, art, history, etc. 
The list of possible subjects for nonfiction writing could be anything and everything. [substeps] Unlike fiction, which is literature created from imagination, nonfiction is structured around real events, moments, practices, and approaches to a subject.