The recent movie inspired me to read Fleming's original Bond classic. Unfortunately, I was a bit tainted as I had already watched the movie. The book was reasonable, but I didn't particularly care for the French that was used often to describe the places and for fancy quips between characters.
The movie stay relatively true to the book but there were some subtle yet significant twists. It was also slightly modernized to reflect the current world political situation as one would expect. The wikipedia list of differences is here.
It is worth noting that I'm far too tainted in general from watching all of the Bond flicks to linkely be able to enjoy any of Ian's books. Unless he wrote some that weren't made into movies, I will likely end up anticipating the story and not reading for enjoyment.