Ah...well...sorry about the lack of detail. I'm kinda lost on how the art world works, that's why.
So...for a thumbnail, I would need someone with knowledge of placing graphics and using he right type of font. I'm planning to do some kind of title, just for people to know that "Hey, this is Background People, come in and read this thing!"
And for the banner. This sounds kinda complicated for me (as a guy with 0 art skills) so I'll try to describe the banner as concisely as possible (along with a bit of the story as well).
So...I think I'll put Dante, Kara, Kat (you'll see her soon) and Nathan (the narrator in the first chapter) in the banner, with the shaded in figures of Dante and Kara sitting together while Nathan and Kara (also shaded) look at them from afar. I guess the figures could be mediumly-proportioned.
The other things, such as hair style or whatnot are something you can be creative with. I haven't described the characters in full yet, so I could always adapt to whatever you will draw.
And again, I'm really sorry if the post sounded a bit vague. I promise, it will get better over time.
If you have any thoughts on the story, please just comment.
Thank you so much for replying to this post.
-Heliox14