I will admit.....I saw the movie first. So there really weren't any surprises for me as far as the plot goes. There were pieces that the movie didn't cover that I thought really expanded my understanding and feelings for the characters.
I thought the movie was ok.....but not great. Having now read the source, I think the movie did it justice. The key pieces were there and the casting was great. It was a different kind of experience for me, seeing the movie first. Its the first time I have done book/movie companions backwards. I think, if I had read the book first I may have had more issues with the movie. But nothing drastic.
I am looking forward to reading the rest of the series. I have already seen Catching Fire as well so reading that will be similar to reading The Hunger Games in that I have an idea of the plot and can compare the two as I go. Should be fun!