There is not at the moment a great deal of advice about how to handle graphic novels in the study of Part 1 of the Literature program and how to write about them. Your teachers will have some advice, but you may find the following TED talk at Dartmouth helpful.
Michael Chaney also mentions one of the most helpful guides to “comics” (which is really what “graphic novels” are, at root): Scott McCloud’s Understanding Comics: The Invisible Art. If there is not a copy available in your classroom, you may want to encourage your teacher to get one. You will find it very helpful in learning the lingo of the form.