Choose an event in your life that would make a good basis for a book. Explain why other people would be interested in reading about your experience.
I would probably be practical and say that a book can be written about my job search. It may help other people better understand how to look for work and the steps they need to update their resume as well as what to wear.
Job searching is really hard work. That's right. I said it. Job searching is a job in and of itself.
The first thing is to make sure your resume looks good. The next thing would be knowing what you are looking for. Next would be a spreadsheet to keep track of the places where you applied and to make a point to call them back after a week. Lastly, make sure your business casual wardrobe is up to par.
Each of these topics can have a chapter all its own.