One of my absolute favorite books when I was a kid in the 70s was Star Gate by Andre Norton, published in 1958. I found it first in the junior high school library, then managed to buy a used paperback copy — probably secretly; my father didn’t believe in letting me buy books I’d already read, even when they were only $1.00 or so. Even as a kid I was careful with books no matter how many times I read them, and it’s on my shelf today.
It’s one of those books that I didn’t realize was deeply encoded in my writing DNA until I went back and looked at it recently. It’s not like I ever forgot about the book, but it and the others like it were so deep under my skin I forgot there was a time before I read them. They formed my understanding of what SF/F should be. I read Tolkien and other epic fantasies, but Andre Norton got to me first, and planted seeds that eventually grew into mountain-trees.