Many questions that new and potential beekeepers have usually ends with book recommendations. Books do not replace actual physical experience, yet the opposite is also true. The knowledge and true reasoning behind honey bee behavior, physiology, and pathogens can not be correctly understood by simple observation.
Beekeeping for Dummies is probably the best book for beginners. The dummies books have a strange title, yet they normally do great research in finding an author to best represent a topic. Picking up a book that is too advanced/difficult to read to start with will only turn you off to the topic.
Backyard Beekeeper is another terrific book for the hobby beekeeper. Either as a beginning book or for the more experienced hobbiest, there is great info in this book.
ABC &XYZ of Bee Culture is an example of a more advanced book, both in scope and size. This book is setup like an encyclopedia of beekeeping related topics. A must have for all serious beekeepers. Make sure you get yourself this new edition, Amazon doesn’t seem to carry this edition yet. You can find it through most beekeeping suppliers.
The Hive and the Honey Bee is the book to buy when you have read your first two above. This book is huge! This book started as a small book written by L.L. Langstroth and has expanded through the years to include 22 chapters by 33 authors. Beekeeping history, anatomy and physiology of honey bees, bee behavior, techniques, equipment, extracting, honey plants, diseases, business considerations, and many other topics are covered in here somewhere. This is severely advanced reading and is not user-friendly to a new/potential beekeeper, yet is essential for the library of anyone interested or progressing along.