Book reviews are not considered research and are generally not used as evidence in a research paper. The purpose of book reviews is to compare and contrast an author's thesis with other scholars' ideas. This means that the book review does not present research, i.e. primary sources to construct a new argument. Book reviews are good for identifying works that you may not have known about, to clarify an author's argument that is unclear, and to summarize competing aguments.
Remember that a book review is not to detail the contents of a book, rather to give enough information about the work for the reader to understand your comments about the work. Some suggestions for the content of a book review: