When you read a graphic novel you start at the front of the book. You will read from top to bottom and left to right just like a normal book. Once you reach the bottom of the page you go onto the top of the next page.
In graphic novels there are many shapes for text on the page. The shapes usually do different things, such as the ones below.
When reading the text you read from top to bottom in a pane (a square) starting with any caption first and then dialogue and thought bubbles in order from top to bottom and left to right.
Illustration and Illustrators. (n.d.). Retrieved March 16, 2017, from http://eduscapes.com/materials/3.htm