Basically, you need to read a book until you have great understanding for it. Once your'e done, write about the major parts of what you read!
Hope you found this useful...
Ex: Lemonade War
Two siblings, one younger and one older fight. The younger one is super smart and was moved up to the older ones grade. There fight went on until they made a bet. Whoever gets the most money out of the lemonade stand, wins all the money