The goal of a scholarly book review is not to summarize the content of the book, but rather to situate the historical merit of the book and to evaluate critically the author's purpose, thesis, contentions, and methods of analysis. Hence, the bulk of your review essay should evaluate the author's contention in light of your own knowledge and with respect to relevant material covered in class. 
Your review should be approximately 2,000 words in length. An essential feature of a good book review is the reviewer's ability to prepare concisely so that a comprehensive evaluation of the book can be obtained in a relatively short essay. Be sure to make references to specific portions of the book to illustrate your evaluation. The challenge will be to do as much of this as possible and yet not let it interfere with the restricted length of the essay. Direct quotations can be very useful, though they should be concise and pithy. 
Perhaps most important, your review should state a thesis in the opening paragraph that (1) describes the author's main argument(s) and (2) evaluates the author's success in carrying these arguments through. Subsequent paragraphs should support your thesis. 
on many thousand are gone by ira berlin.