The two objectives of a book review are to describe the work and to provide a critical evaluation of the work within its literary genre or academic discipline.
As you read the book you should consider the following critical questions:
Purpose - why did the author write the book?
Authority - what are the author's qualifications on the subject?
Content - what are the author's main ideas or themes?
Style & format - how well does the author express his/her ideas?
Significance - what new information does this work add to its discipline?
You may wish to make notes and select quotations from the text that will support your point of view. Also, you may want to consult other reviews or texts on the same subject or by the same author.