Writers don’t always make the right decision when choosing whether or not to mention self-published books in query letter bios. And while this isn’t a black-and-white issue, we’ve prepared some basic guidelines to help you make that decision. (Note: Keep in mind that the guidelines listed below are related to mentioning the existence of self-published books when querying a different, unpublished manuscript. If you are querying agents with a self-published book, there are different “best practices” to follow.)