It's good in our craft to write book reviews for our successful author friends and other authors whose books we read. When I read reviews on Amazon and other online book sellers, I read a lot of book reports instead. What's the difference? I did some research and one of the most informative blogs I read was Book, Line and Sinker.
Think of the letters in "review" as your reminder how to write a review.
R Relay basic book and author information.
Title, genre, something about author.
E Explore the content. Write an overview. Don't give away too much of the story.
V Voice your opinion. Credible characters? Authentic dialogue? Problems?
I Issues. What issues does the book discuss? Is the book issues driven?
E Elements. Discuss exposition, characterization, symbolism, etc.
W Windup your evaluation. Make your point.
Write enough to inspire readers to read the book without killing the story. How do you write a review? a little review and a little report? Which helps you determine whether you will read the book someone else reviewed?