How do you study school books?

If you mean a textbook, the best way is to use the headings and the questions at the end of each chapter. Copy the main headings into your notes, then add any words and terms that you don't know. When you study for your test, you'll use your notebook instead of the book. Make sure you know the answer to each question at the end of the chapters, because those check to see if you learned what you read.