American Gods.... now that's one of those books that I love like it's a friend. It's up there with The Red Tent.
When I was almost 9, my grandmother began a mission to turn my cousin that was my age and I onto mythology. I became deeply entrenched almost immediately- she bought us both a copy of D'aulaire's Greek Myths. I was easily sated for every Christmas after, while, my cousin's attention wavered. Which sucked, cause she kept getting cool stuff like the game By Jove, while I kept getting books I could have gotten myself
But I recognized when I was a pre-teen that I wasn't going to learn much more about Greek Mythology without getting into classical literature (which I wasn't ready for)- so that's when I branched out.
I will say, though, The Red Tent is what sparked my current passion for Near East Mythology.