LOL, if you've read the books, the TV show has no spoilers... 
My friend always prefaces it by saying, well, now that this happened on the show, let me tell you how it really happened in the book and how this/that was left out. Sometimes he's not sure if it might be something later or if it's just glossed over completely.
Also I believe it was mentioned that books 5 and 6 occur at the same time from different perspectives so it could affect how we watch the show.