Diane asked me if Manga Studio is good for setting up a whole book. I have a few words on this in the video below.
Of course it is important to have a good communication with the company that is going to print your artwork.
No matter if you are publishing a graphic or a normal novel, you always have to reckon with the thickness of the paper and other aspects. Your contact person at the printer will tell you precisely how thick the book will be and thus how wide you have to design the spine of your book.
Once you have all the data you need you can start designing your cover.