Choose an age group and genre. Two of the most popular genres for children's books are realistic fiction and fantasy. More specifically, books that are humorous or have supernatural characters or magic also are widely read. Think about what kind of message you want your book to have.
Form a chapter-by-chapter outline. Each chapter should have a beginning, middle and end. Your book should be character-driven. Writing character sketches can help keep track of your characters. Consider the age, appearance, personality, background history, friends and family of a character when sketching out these details.
Decide how you want to write your chapter book. Do you want to use first person or second person to narrate your story? What is the setting of the story? What is the mood or tone?
Develop the plot. Ask yourself the following questions: What problem is the main character going to face? How will he overcome the problem? This is the conflict of the story, which builds suspense and keeps the reader interested.
End your novel with a solution to the problem or conflict resolution. Children's chapter books often deal with everyday problems that children face, such as a friend moving away, a school bully and making friends.