Practical nonfiction includes anything that is primarily instructional, whether it's self-help or pet training or knitting projects or dating how-tos. It is absolutely vital in this area to be aware of what books might compete with yours, and to propose a book that is in some way distinct from what's already on the shelf. It's also important to realize that when there is no competition there might be a very good reason for that. The existence of a need is quite different from the existence of a market. Quite often a need exists in part because there is no market--that is, the same resistance that the book would find has created the need. For example--men don't buy self-help because they don't want to be fixed, and if they wanted to be fixed there wouldn't be so much wrong with them. If people need to read your book to realize they need to buy it, that's a problem.

Parenting books tend to sell best to parents who have a diagnosis of a special need of their children or parents with very young children, or, better, not-yet-born children. That is, pregnant women buy a lot of books.

Craft books have the advantage of selling outside of the book trade and that, as of this writing, inexpensive e-books aren't directly undercutting the market. They do however seek to serve a community that gets a good deal of patterns on the internet for cheap or free. Therefore a book has to have really knock-your-socks-off patterns and a cool concept that really stands out on the shelf.

Diet how-to books aren't generally my thing.

Cookbooks have to be very distinctive to have a fighting chance if you're not a celebrity. TV personalities rule this shelf.

Health and business books are particularly dependent on author credentials.

In pet books, dog books are generally stronger than cat books.

Spiritual books are often too abstract for me.

Credentials are very important for practical nonfiction. Practical nonfiction has formed the backbone of my business; I love it and I look forward to hearing from you about it.