Heres Frederica Mathewes-Greens review of the movie. Her advice: read the books.
Not having seen the movie yet, but generally believing that even good movies rarely satisfy fans of the book, Im inclined to agree, but also to add another piece of advice. Get the books on tape; you can order them from a page on this site. Why books on tape? Two words: Tim Curry. He reads most of them and does an absolutely wonderful job. (Daniel Handler--aka Lemony Snicket--read a couple for the tapes and wasnt nearly as good.) We discovered the pleasures of Lemony Snicket as told by Tim Curry a couple of years ago on a road trip that took us from Atlanta to Indianapolis to the D.C. area and then back to Atlanta (roughly 33 hours of car time, with two kids then aged 7 and 5). Everyone was enthralled by the stories.
Since then, weve made our way through "book the ninth" on road trips, stopping at Cracker Barrels for meals and to trade in books weve finished for books we havent yet heard. (Cracker Barrel sells you the book-on-tape and then refunds you most of the money when you return it. The only problem with the system is that you can never be certain whats going to be in stock when you get to the restaurant. We havent been able to locate tapes of books 10 and 11, despite some rather ridiculous efforts, which has driven us back to DVDs with wireless headphones to head off the "when will we be there?" chant.)
My wife and I will, nevertheless, go see the movie and may then take our kids, if it seems appropriate and not too dark and scary. Youthful imaginations in the Knippenberg household are extremely vivid and produce nightmares at the drop of a hat.