I have a friend named Michael Ellis who is an illustrator (hi Mike) you really should check out his work.
He posted a wonderful image of traffic in Marrakech which prompted me to ask that he get cracking on a graphic novel.
I was mostly joking because Mike is plenty busy and a graphic novel isn't a project that can be completed without a tremendous amount of effort and time. I should know since I have two failed novels under my belt. I use the dramatic failure tag because I gave up on these projects, but to be more accurate I should call them "Learning Experiences: Volume 1 & 2". Here are the cover images (I will go cringe in the corner for a moment).
The best way to learn about making a graphic novel is to make one (or two). Not all of us can afford to take the blissful plunge into a four year degree plan at The Center for Cartoon Studies . There are some relatively affordable online courses created to provide support for someone trying to revive a drowning graphic novel.
My favorite affordable and useful resource is Drawing Words and Writing Pictures by Jessica Abel and Matt Madden. There are two textbooks in the series and they are pretty thorough from supplies to scanning specs. Once you ingest the techniques the books are still great to have around (like your car manual) to refer to on the occasions when your project bursts into flames.
Though I love a fine graphic novel and would love to publish one in the future I ended up presenting my first book as a webcomic. I now use the techniques I learned from the novel making experience to inform my current work. It's amazing how well the rules of a readable comic page translate into an info-graphic about fast food market share.