The low carb bible is a large scale, hardcover book with a ton of information. It compares the various diets, explains why they work and offers practical recipes and tips.  The book doesn't try to indoctrinate you in the low carb lifestyle. It gives information both in support of low carb diets as well as the concerns that some have about this lifestyle. 

This is a great book to leave on your coffee table and read in many sittings, looking over the exercises one day, the various diet suggestions on another. A great way to get a grounding in the low carb world.