Reading the book and watching the movie made based on the novel is a risky thing to do and a double edge sword. Best case scenario, it can give you an extra and make your experience better, but it can also destroy it. Reading the book gives you the freedom of imagining everything your way. When watching the movie, you don't have that luxury and the images you see can overwrite and even delete what you have previously imagined. For me it's always bitter sweet.
I know right? Luckily it didn't destroy the whole thing for me, I actually like the movies a lot, but there's nothing like reading those words and creating the images in my (very powerful and active) imagination.