Read the book with a notebook beside you. Make notes regarding the pacing of the story, especially regarding how quickly the inciting incident takes place. Make notes regarding main characters, secondary characters and how these characters interact with one another and the story's plot. Note themes and metaphors the author uses. Summarize your take on the story as you go, in concise sentences you can use when you write your review.
Summarize the story and the plot. There's a difference between the two. A story is "about" and the plot is "how." Write a brief one or one or two paragraphs detailing what the story is about first, then jot down specifics regarding plot points--how the author tells the story. The plot points should be places in the story where the author twists the story or adds an element of surprise, a new direction, or when characters reach or overcome a roadblock.
Write notes on main characters and secondary characters as they appear in the story. Give a summary of the characters, their goals within the context of the story, and how each of these characters relate to one another. Write a brief character description of important characters and some of your thoughts about character believability, the integrity of the characters, and whether or not the characters are well developed.
Make notes on the overall telling of the story. Questions you will want to address in your review should be written in your outline. Some of the questions you should consider are: does the inciting incident come quickly? Is the book a slow-paced or fast-paced read? Does the plot provide a sense of thrill or mystery? Make notes about the complexity of the plot and any secondary story lines. Answering questions for readers is the purpose of a book review.
Make a note of the book's main theme and whether it is evident or implied. Make a list of the metaphors you find in the book you will want to write about in your review.
Summarize in two or three paragraphs your impression of the book. Personal opinion separates a book review from a book report. Write down your overall impression of the book's entertainment value, the skill level of the author, and how you will recommend the book in your review.