The family unit and the relationships among its members has always been a topic of interest for readers, especially with the advent of “extended families,” and “significant others.” While many of these books are written by acknowledged authorities, if you choose to write a book in this genre and don't possess the expertise, in many instances you can do so by relying on research, interviews, and your own experience. Writing a parenting, family, and relationship book can be an enjoyable experience since stories and anecdotes are frequently employed.