There is no particular format or style to write a review. It depends on the creativity and interest of the person writing the review.
Provide brief bibliographic information about the book.
Give the title of the book as the title of your review.
Include title, author, place, publisher, publication date, edition, pages, special features (maps, etc.), price, ISBN.
Write the subject/theme of the book, fiction or non-fiction. What is the central theme and main characters of the work, in case the book is a fiction.
The purpose and intent of writing the book. Identify the target audience – like is it a book meant specially for children? What category of a book it is?
Technique (s) and styles adopted by the author like the style of narration. How the author has presented the story or the subject content of the book. Is it interesting?
For subject books, valuate the accuracy, thoroughness, clarity and usefulness to the reader.
Write your personal experience reading the book – how do you relate to the characters in the book, what you liked most about the book, would you recommend this books to others, to whom the book is suitable etc.
Will you recommend this to others? In your opinion, which category of users it will be more useful or interesting? If this is the best book you have ever read, say so — and why. If it’s merely another nice book, say so.
Your conclusion should summarize, perhaps include a final assessment.