The books get longer as the series continues, but at 342 pages, The Chamber of Secrets didn't take us too long to read. Once soccer season finished, we had more time and finished up the book pretty quickly. Once we saw we were near the end and would finish before the weekend, we headed to the library to check out the movie. The movie itself does a pretty good job following the book. It kept pretty much every important scene, leading to a long movie of 161 minutes. There's a few differences, but nothing major.
We've had a blast reading the books and watching the movies. My 5 year old laughed hysterically during several scenes of The Chamber of Secrets! She got a bit scared during the spider scene, but it was nothing that terrified her or gave her bad dreams.
If you're looking for something to do as a family, reading books together is a great idea!