I'm purposefully not re-reading the books and keeping my memory of the details fuzzy. That way, I won't be too disappointed with changes. I've read some spoilers of the changes and think that will actually help my enjoyment. I won't be caught off guard. I am seeing the movie Saturday. I loved the first movie.
My biggest complaint with the Lord of the Rings movie adaptions is I felt they completely ruined Faramir. Very frustrating. Overall, the movies did a really good job. The last movie disappointed me the most. The Hobbit trilogy was unwatchable for me.