Hmm. I don't think there is any such resource for the kind of thing you're asking. If you have the technical skills, then it sounds like you're just struggling with how to actually go about coming up with a logo.
What may help is if you broke it down--try googling "logo design concepts" or something to give you ideas about how to embody your logo concept.
Look at published authors who have websites designed to fit the color scheme of their book; see how they pulled in the book colors, concepts, and images, and see how that effected their website banner.
Also look at authors who have a lot of promotional swag--Beth Revis (author of "Across the universe") comes to mind--and analyze what visual elements they used to pull it all together with a common theme. (Revis is a good example because her novel focuses on a spaceship, and her cover art team actually designed a logo for the spaceship itself, which she was then able to book on things like T shirts and water bottles, etc.) Figure out how people use logos.
And finally, I'd really suggest looking at images and concepts associated with your genre. Look at authors published in that genre and what colors are on the covers of their books, what images are used. You have fantasy and urban fantasy. So what images really identify each genre? Do they overlap anywhere? Break it down into as many small pieces as possible.
Anyway, I know I basically suggested a lot of research for you, but I hope that at least got the mental process going and gave you some ideas!
Best,
-Mandy