Find your niche. Everyone is an expert at something. What are you especially good at? Consider your job, your schooling, your social life and your hobbies. Make a list of everything you can think of that you are an expert in (or can at least do research on).
Cook up a cookbook or two. Surprisingly, cookbooks sell rather well, especially if you can tailor your cookbook to a specific type of cooking. “Cuban Cuisine for the Overworked Mom” will find a wider market than just “Cuban Cuisine.”
Delve into the past. Genealogy books are great types of nonfiction. Roam the cemetery in your local town and copy down the headstone engravings. Then write a book that lists everything that you found. Family researchers crave this type of information. Your title could be “Rosewood Cemetery Headstones.”
Offer your nonfiction in downloadable form. There are many places on the Internet that offer this service. Lulu.com is one source that allows you to upload your book and sell it on their marketplace in print or as a download. The cost to you is nothing and you set the price for the download.
Teach a workshop. If you are an expert in something and you write a book on that topic, then consider teaching a workshop in your community. If you are an expert at Memoir Writing, then teach a workshop on Memoir Writing. Check with your local Adult Education Center, local community centers, local library and area churches. Most of these places will not pay you for teaching the class, but you can sell your nonfiction book there.
Reserve a spot at area fairs and festivals. You can set up a booth or table and sell all your nonfiction books at one time. Fall and spring are the best times for these types of venues. Call your Chamber of Commerce for more information on upcoming fairs and festivals.
Send a query to book publishers to see if any are interested in publishing your nonfiction book. Many book publishers have instructions on their websites about how to submit a book idea or a book manuscript.