It was a really tough decision, but I decided to wait to read book two until after season two airs this spring. My reasoning is that the books go further in depth than the show, so there will still be some surprises and things to be revealed in reading it after season two. If I read the book now, I'll know absolutely everything that will happen down to minute details. Plus I really like being surprised visually, if that makes sense.
So that's my thinking. But believe me, I've been tempted a few times. Luckily my reading list is fairly lengthy, so I've been busying myself with other books.