I'm not going to try and do an in-depth analysis of the movie. There are other people who are much more qualified than I am for that. I've only read the book twice, most recently prior to the release of the first LOTR movie. Some of the details are a little blurry, to say the least.
On the whole, the movie matched the book quite well, at least to the best of my memory. There were a few details I thought were different. I know Jackson is embellishing the story a little, drawing on sources in Tolkien's writings other than the novel itself. Those scenes were fairly obvious.
The cinematography was great. Every time I see one of these movies, I want to move to New Zealand.
One thing I did find interesting. With all the running the party did, I was impressed that no one ever seemed out of breath, especially since it was in the mountains.
On the whole I was impressed. This is one I'll be getting on DVD.