All types of writers are adapting their stories as graphic novels as a way of increasing their audience reach.
Creating Graphic Novels: Adapting Stories for a Multimillion Dollar Industry provides information on the special needs of a graphic novel script, how to find your art team, and your publishing options. It shows ways a creator can plug into the audience of comic book and graphic novel readers.
The relaxed, conversational presentation will help you think graphically for the writing and pragmatically for the business concerns.