Now, because the books were published sort of out of order in the beginning, the order of reading these can be a bit confusing. I like to start out with The Magician's Nephew, which was originally published as the sixth in the series, but is a prequel to it all. You'll get to know the very first human venturers in Narnia, Digory and Polly, and their troubles with Digory's odd Uncle Andrew.
The original first book, however, is of course The Lion, The Witch And The Wardrobe. In this we skip forward many years after Digory and Polly's adventures, and join the Pevensies, Peter, Susan, Edmund, and little Lucy. The siblings go away to live in a large house in the country, and Lucy discovers a magical wardrobe which appears to lead to another world.
After this, instead of moving on to the original book two, Prince Caspian, I prefer to read The Horse And His Boy, which although at first it may seem to have nothing to do with Narnia, actually takes place during book one.
So, you get the picture! C.S. Lewis' immortal series is one of the best, and if I dare say, way better than the movies. Happy reading, everybody!