There will be complaints that they have missed out the first book, but film making has different priorities. This film is a pretty good realisation of C.S. Lewis's imaginary world. New Zealand provides the scenery, as it did for Lord of the Rings. It's about four children who find their way into another world via the wardrobe and end up as part of a great battle between good (the lion) and evil (guess who?). The kids do a pretty good job of acting. Tilda Swinton is suitably evil as the witch. Most of the rest of the cast seems to be computer generated to at least some extent. The effects are not quite up to the standard of some other recent films, but good enough to tell the story and keep the kids happy. It gallops along at a good pace. I enjoyed it, but it didn't require too much thought.
There has been a lot of comment about this film having some sort of Christian message. Okay, so there is a sacrifice/resurection element and a few other connections, but I don't think it really matters. I don't know enough of the Bible to comment further, but surely all these mythical creatures fighting for good would not be welcome in your average church. I've just been watching some of the extras on the Two Towers and mention is made of Lewis being an atheist, but other sources say that he converted before he wrote these books.
There's an official site at Disney, but it's not too exciting.