I had a hell of a time figuring out how to make a graphic novel by myself. The White Donkey was done through a lot of trial and error. Here's a short list to help you get started!
  1. Figure out your story
    This is harder than it sounds. You need to know your story before you start writing. Ask yourself the most important question: What is the point?
  2. Write a detailed script
    Don't even think about drawing a single panel until you know exactly every bit of your story. Every line of dialog and every action needs to be spelled out clearly.
  3. Have a vision
    Know what this story is going to look like visually. Figure out the art direction, what medium you're going to use and how to best serve your story.
  4. Design the characters
    You're going to have to draw these same characters many times over the course of your book. Have character sheets to refer to from every angle.
  5. Layout your pages
    How do the panels interact with the reader? How can you use the book itself as a medium to tell your story? Think of ways to interact with your reader to create an immersive experience. In the end, how your reader reads the book is more important than what you're actually putting down.
  6. Draw
    It's not gonna get done until you get it done. Don't half-ass it, but remember that most readers only spend about 3 seconds on each panel.