How close is the show to the book A Game of Thrones?

Watched the season end of Game of Thrones. Loved the show so much I simply cannot wait until next year for season 2. I was thinking I'd pick up the books see what happens next. So this question is for anyone that has read the first book and watched the entire first season of the show.



How close is the show to the book? If I just jump straight into the second book will I be pretty much caught up? Or will i be missing anything that the show didn't put in?How close is the show to the book A Game of Thrones?
The first season stayed very faithful to the book. Most dialogs and lines came straight out of the books. The TV added certain scenes that are not in the book to clarify events and develop characters, and those scenes add to and do not contradict the book. The TV also made certain changes to the book, and most of those changes are fight and battle scenes, mostly for budgetary reasons. IMO, some added/altered fight scenes (like the one between Ned Stark and Jaime Lannister, and how Khal Drogo ripped out his opponent's tongue) are actually better than those in the book. Tyrion's battle was eliminated due to budgetary constraint; in the TV, he was simply knocked out to skip the battle.



The season finale actually covers some early chapters in the second book: Lord Mormont led two hundred rangers beyond the Wall to investigate the wildlings and undead threats, and Yoren disguised Arya as a boy to sneak her out of the city. Those events are in the early part of the second book, but the first season finale move them forward to provide cliffhanger endings for Jon Snow and Arya.