Oh, Choco, I totally agree. If you read all the rumours, at least one is bound to be right and that's going to ruin it for you. I mean, my sister told me Pro. Lupin was a werewolf before I read Prisoner of Azkaban, and that ruined part of the enjoyment for me.
Don't even read the rumours. They just confuse me, and it's so much more fun if you just hear it for the first time when you read the book.