The most common is the opinion on a literary work or book as a whole. The first thing that must be noted in the review, it is information about the author and the book. Briefly describe the life journey of a writer, the year when was created the book, the background of its creation. Specify the name of the book, its meaning, and I wanted to tell the author.
Then describe their impression about the reading, what do you expect at the beginning, it lived up to your expectations when reading, whether you liked the ending. But do not paint the details of the story, the future reader should be interested in reading the book. So don't reveal all the secrets and intrigue, only describe your attitude as you read the book.
You can briefly describe the scene and the main characters. But again, write about them from your point of view, the essence of the opinion in your personal perception of reading and books in your personal attitude. Maybe someone's opinion will match yours and some don't.
In addition to the future reader having a full idea of the book, it is important to write about the language and style of the text, relevance of the topic, the author's intent.
After that, you need to specify your opinion in General. Tell us, liked or not liked you book, what you think about it, whether your view with the author, how reading the book affected you, left any trace in your soul. Specify, recommend or no you ebook readers evaluate the work. And also write, would like you to read it again and would you read other works by this author.
Also, try to assess the situation and what mood it is better to read this work.