Ricky Smith wrote this wonderful article about starting:
Introduction to Card Magic
Starting off right can be done in a variety of ways depending on your desires and how much you are willing to invest to start out. A cost-effective and proven book for beginners is the Royal Road to Card Magic, which will teach a variety of techniques, flourishes, and effects, while setting up the beginner with a thorough grounding in the theory of the art. This book will teach you valuable lessons in a straight forward manner that will be beneficial and prove valuable throughout your studies, even at the highest levels of understanding. It is a bit antiquated in some aspects, like writing style, but the study will contribute greatly towards your ability to comprehend other books further on in your career. As a bonus, R. Paul Wilson, an excellent magician and thinker, has a superb DVD set that focuses on this book which will aid in your understanding of the work and magic in general immensely.
Another path one could take which is more modern and thorough, in my opinion, is Roberto Giobbi’s Card College. These books represent a greater investment than the Royal Road but are absolutely fantastic. There are five books in the series and purchasing all of them to start out with may be a little extravagant, so I would recommend getting the first two to start if you are hesitant. The first book is an excellent starting point and will get your hands accustomed to some of the commoner sleights and build your dexterity, while the second book will take you into some more advanced techniques and tricks putting you well on your way to becoming an adept in the art. The next volumes feature many more techniques and theory that will really round out anyone’s education in the art, and they are highly recommended. The whole series really represents a practically complete understanding of the art consolidated within its covers, and one could easily be considered an expert with just the knowledge contained in these books. Regardless of the path you choose, omitting the study of some form of basic text is ill advised; it is likely that your study of more advanced books will be hindered without a good base knowledge of the art.
Here is the full part:
http://dananddave.com/academy/professors/ricky-smith.html