Some good stories, here!
Mine's a bit long, so bear with me.
I was probably about 9 or 10 when I went with my parents to visit a new church member. My father's a pastor, so this kind of thing happened a lot. She was reading It and had the trade paperback on her coffee table with a bookmark in place. Dad questioned her about it and she made light of it, but I was intrigued. I had a friend, another pastor's son, who was three years older than me. I discovered shortly after noticing the book at the new church member's house that both he and his older brother (who seemed nearly an adult to little me) had read King before, and they both played him up as a writer who, if I were to so much as glance at a page of one of his books, wouldn't sleep for a week. I never forgot his name, and every time I saw a book of his in the library, I got more intrigued.
When I was in eighth grade, I borrowed Pet Sematary from a different friend. I had seen the Publishers Weekly quote that was plastered on the back of it - "The most frightening book Stephen King has ever written" - when my friend had shown me his copy and I decided this was the place to start. I read probably a third of it. Maybe less. Church had just come back to life. The reason I gave it back unfinished was because I knew that if my parents, particularly my mother, found me with it, I would be severely punished, so I could only read it when I was sure they weren't around to catch me. Finally I gave it back to my friend only partially read, knowing that trying to finish it would likely mean keeping it well into high school.
I read The Green Mile years later and just adored it. That's the book that turned me into a constant reader.