I was in high school when a friend walked up to me and very excitedly said 'You have to read this!!' and handed me a paperback copy of Carrie. I looked at the cover (all black with the picture of the girl, no author's name whatsoever on it) turned it over and read the back, opened it up and read what was on the first page. I handed it back to her and said 'No thanks.'
The first King book I read was 'Salem's Lot (in paperback) and that scared the crap out of me! It was the same scenario- a friend handed it to me and said that it scared her so much she couldn't sleep for days. I looked at it (all black cover again with no mention of King) turned it over to the back and read 'The town knew darkness...but no one dared talk about the high, sweet, evil laughter from a child...and the sucking sounds...' That did it for me! I was ready for this one! I think I read it in two or three days. Lost some sleep, too. Haven't looked back since....