Read and take notes about the book. Be sure to make note of the sources used in the footnotes or end notes.
Go to the original sources the author used, and make notes about them as well. Look to see if the author used his sources properly. Determine if he parsed them, or used unreliable sources.
Write your introduction, describing the book in a general way and naming the author.
Write a sort summary of the book. Do this in the same sequence as things are laid out in the book. Avoid giving every detail. Instead, use the notes you took to highlight the major points the author makes.
Write a few pages -- or more, depending on the requirements -- or the number of sources in the book. Then do a section about the secondary sources.
Evaluate, based on the notes you took earlier, how well the author used his sources and how effective they were for his purpose.
Evaluate the arguments the author puts forward. Look for flaws in his reasoning or any demonstration of bias.
Summarize your opinion about the book in question, and support your views with logical arguments and cited evidence.