We recently read all 5 books in the Spiderwick Chronicles for bedtime. These books were so enjoyable, and they were really quick reads. We really wanted to finish them before the movie came out (or at least while it was still playing), and we managed that. More on that below.
The story goes like this. The Grace family (Mallory, Simon and Jared (twins), and their mom) move into a very old house belonging to their Aunt Lucinda, who is in the "nuthouse." Their parents are having marital problems, thus the move. Jared discovers a field guide to magical beings written by his great-great-uncle Arthur Spiderwick (Lucinda's father), and crazy things begin to happen. They must keep the field guide out of the hands of the ogre Mulgarath or else.
As I said, we all really liked the books.
I had heard great things about the movie and had high expectations when we saw it today. As a stand-alone movie, it was very entertaining, but it strayed very far from the plot of the books. Well, no, if you take the basic plot, it's the same. Keep the book away from Mulgarath. But very important parts were left out (like the entire 4th book) and unnecessary details were added (did they really need to say that the dad had moved in with another woman, for example). All of the main characters were there, but the movie only vaguely resembled the great books we just read. I wouldn't say don't see the movie, just be forewarned that a lot is changed.