For toddler children age 0-3
Naming things; Children at this age are interested in learning about the things surrounding them. Using only a word to tell every object's name to children with an illustration could help them memorize. For instance, naming body parts, animals, plants, toys, food, and so on.
Comparison and opposites; As they grow, children will learn and explore the things around them, also they’ll learn about the comparison between big and small, loud and quiet, high and low, and etc. Using this topic, you could make it interactive with children by asking them questions and make them think which one is the correct opposites.
Simple stories; Topic for toddler children usually feature one character and an easy story plot with some actions involve. For instance “Brown Bear, Brown Bear, What Do You See?” by Bill Martin, Jr, and Eric Carle that just simply tell about animals with their body colors who are interacting with each other.
For kindergarten children age 4-8
Making choices; The topic for kindergarten children should be varied since they’ve started to learn how to read and understand. Children’s books for kindergarten children could be about a character making big choices with some consequences that they’ll be facing. Or maybe just simple choices such as choosing a pet, clothes to buy, food to eat, and so on.
Following or breaking rules; Books about characters whether to follow rules or breaking them is another good topic to choose to write about for children’s books. This will teach children that it’s okay to make mistakes and take a lesson from them. As long as we’re responsible for our choices.
Making new friends; As they begin to start kindergarten, stories based on this topic is relatable to them. Since they’ll be making new friends in kindergarten, this will encourage them to socialize with new friends and enjoy playing together as they get along. Other than that, they’ll start to learn to cooperate and share with others in a friendship.