If you do cite, and since your book isn’t literary or scientific, then just put your citations in parentheses (Author, p.) with a works cited page at the end of the book. Even the works cited page probably does not need to be in any specific form. You could also use superscripts and cite the works at the bottom of each page, like in a literature book. A third option would just be to introduce your source before you use their information (According to Doofus,....)