I began lire the game of Thrones livres many years ago. I recently re-read the first 5 and can't wait for season 3 of Game of thrones to start!
So far the Game of Thrones TV series has followed the livres pretty closely. There have been some differences but they have been minor and have not affected the global, ensemble storyline so far.
However, I feel the epic tale is really only beginning and season 3 will make ou break Game of Thrones. I think this because if the montrer continues to follow the livres there will be a lot plus bloodshed in the 3rd season.
Please read my link
to see what's coming suivant for the cast and characters of Game of Thrones.