By KDP's measurements:
Spine width: 0.8475 inches
Cover width: 13.0975 inches
Cover height: 9.25 inches
My original idea for the cover was very basic; a grandfather clock with roman numerals on a black background and a golden glow coming from behind it.
However, that was before I decided to use designers who know what they are doing, so it is up to the designers if they want to go with that design or make one that is more detailed.
For ideas, the grandfather clock is a portal inside a house, but on the other side of the portal, it dumps the travelers in a thick forest with a tree shaped like a V. The forest is very calming and peaceful; nothing dark and creepy about it!
I would like a grandfather clock with roman numerals somewhere on the cover, or even just the face of the clock.
If the designers want to include people on the cover:
Tosh: A red-haired, green-eyed girl who is tall; 5'10. Typically wears long sleeves and shorts with canvas shoes; her hair is almost always in braids.
Chani: Short (5'0) beautiful female from Thailand with her bangs across her forehead and long black hair.
Tucker: 5'5 boy with messy brown hair and dark-rimmed glasses. Dresses like a stereotypical nerd
Garrison: 6'0, blond hair, blue eyes. Has an elven like face and the build of a baseball player. Wears flannels and baseball caps (usually backwards)
I like fonts that are classy and timeless. I typically go for Serif fonts, too.