Good thread, Peter T.!
One of the books that influenced me early on was Dr. Suess' "Horton Hears a Who". Got me considering "the other", before the term existed.
Mark Twain's "Letters From the Earth" is one of my "desert island" picks. I first read it while in my early teens. That turned me on to Twain's writing more than Huck or Tom did. (I remember reading those books in an interesting format - kind of reversible books- Tom Sawyer on one side & turn the book over and the back cover is the front cover to Huck Finn. Good Companion Library, or something like that?)
Let Us Now Praise Famous Men - James Agee, with photographs by Walker Evans hit me pretty hard as well.
"Mickey Mouse Goes to the Moon" holds a special place in my memory, as I won it as a prize for spelling in kindergarten. Pretty much peaked academically, there.