So, when you are telling a story and focusing on Karma in that story, you can look at it from two different angles: looking forward, you can focus on how do the actions in this story will lead to good or bad consequences in the future or, looking backward, you can see how the events of a story are actually the result of actions that happened in the past. Every single story involves Karma; all action is Karma. If you choose to do your Storybook about Karma, that means you can include any stories at all, and your task is to choose the stories that best illustrate the aspects of Karma that you want your readers to understand.
To find out more, you might read the Karma article in Wikipedia, and also the article on Karma in Hinduism. You might also get some ideas from looking at these Storybooks about Karma from past semesters of this class.