Its great that you want to write a great book review.
A good book review has 3 parts:
A. About the Book
This should ideally be the shortest section of the review. Tell the readers a little bit about the book – its author, genre, topic, and other basic knowledge. Try to keep spoilers out, especially if its a story or thriller, but do try and put hook questions that will keep the reader engaged and take them to the next section of your review. For example, in a mystery book, instead of “A boy finds a giant peach in his backyard.” Try “What happens when a young boy finds a giant peach in his backyard? Does he invite friends to eat, or discover that it is a spaceship?”
B. Your review
This is the longest part of the review. If you are writing a 250 word review, about 125-150 words will come here, or about 50-70% of your total content.
Here are some things that you can cover in this section (depending on the length of your review, of course)
> Your expectation from the book when you picked it up or how you came to read this book.
> The initial impression of the first few pages or words if it was different from the rest of the book.
> What you liked about the book .
> What you did not like about the book.
> What you wish was different in the book.
> Any other observations as a reader.
Of these, of course, what you liked and did not like about the book is the most important. Without that, its not a book review.
C. Conclusion
This should form the rest of the book. Here, you sum up your review in a few words. Some things that you can put in this section are:
> Who is this book most suitable for?
> What age group should read this book.
> If you want to, you can give a rating out of 10 or 5. This is YOUR rating, as a reader.
And that is all it takes to review a book! Go for it! Good Luck!