This is the order the books are now printed in, however they are not the order the books were written in. The order has been changed so that they are read according to the time in which they happened. The order in which they were written is, in my opinion, better to read them in. You will find them more mysterious, and it will make reading the Magician's Nephew far more exciting.
Here is the order in which they were written.
The Lion, The Witch, and The Wardrobe
Prince Caspian
The Voyage of the Dawn Treader
The Horse and His Boy
The Silver Chair
The Last Battle
The Magician's Nephew
