Here's one plan that might work for your kids if they're not sure how to get started.
1. Choose a book you think you can write about. It may not be your favourite book, but it needs to be one you can describe to others.
2. Read the book. If you read it a while back, read it again, just before you write your review.
3. Think about what you've read. Try to answer SOME of these questions in whole sentences:
What was the book about? Try to describe it in a couple of sentences without giving away the ending. To see examples of this, there's a fun site, Book-A-Minute, that condenses well-known books into a sentence or two.
What was your favourite part of the story? Why did you like it?
Who is/are the main characters? Tell us something about them. What happens to them in the story?
What sort of book was it? Was it a picture book, a chapter book, a fantasy book, a nonfiction book for sport fans?
If there are illustrations, how did they help tell the story?
Did you like the book? Why or why not? What was good about it? Did any parts make you laugh? Which ones? Did you feel as if you were looking through the main character's eyes?
What sort of people would like this book?
4. Look at the sentences you have written and see if they can make the bones of your book review. You might need to add some more.
5. Write an interesting starting sentence for your review. Some people like to start with a question. Other reviewers like to start with the book facts: author, illustrator, and publisher to make it easy for others to find the book.
6. Put the sentences you've written into the order that seems best to you. Add any words or sentences you think might make it clearer.
7. Read your book review aloud to yourself and check for spelling and punctuation.
8. Ask someone else to read your review and get their opinion of it. Make any changes you think you need.
Remember, this is just one plan you can follow. Read some book reviews to get ideas, then go ahead and make your own plan. When you're finished why not send your work to a magazine or website that publishes book reviews by kids? You might try Alphabet Soup or Yabba (go to reviews/write a review) (Australia), Building Rainbows (UK) Reader Views (US) or your own local library.
If you're interested in helping children to write, check out my articles: Writing Fun for Kids - Create a Caption, Fast and Fun Writing with Kids, Children's Writing - Write a Procedure, Get Kids Writing with Lists and Online Resources for Reading and Writing.
[This blog post is part of the July Carnival of Children's Literature, held at the wonderful Playing by the Book blog.]