I am also a fiction novel writer who was interested in making one of my novels into a comic series. I did a lot of research and read those Scott McCloud books as well. It is somewhat difficult to reduce a full novel into a comic script but it can be done. My comic so far has turned into a multi book series.

I will tell you that once you convert one novel successfully into a comic script you will feel compelled to convert a lot of your other work. It is so much fun once you get the first couple books out. When you find an artist that makes your work come alive it's amazing. Good luck to you!!!