If you are intending to study for the CCNA exam on your own by using CCNA books, rather than taking a course at a school or other Cisco authorized training partner, you might be confused by the vast amount of CCNA preparation material out there. Here are 3 types of books you will definitely need in order to do well for the difficult Cisco CCNA networking certification exam:

CCNA books (self study) - These are the books which provide the main learning and technical material for the CCNA exam. The good books are closely aligned with the CCNA syllabus and updated regularly to keep up with the changes that Cisco makes almost yearly to the CCNA exam. They are usually of a high quality and are written by highly qualified and experienced network engineers. These authors usually have a high-level Cisco technical qualification such as the CCIE (Cisco Certified Internetwork Expert), which is the highest level of technical certification given to Cisco network professionals. You should be looking out for such qualities when choosing a good CCNA preparation book.
Exam cram books - These are the books you should be looking at once you are finished with the self-study books. At this point, you should be familiar with the technical written material and understand all the necessary concepts required to pass the CCNA exam. These exam cram books serve as a last minute revision so you can remember the essential concepts required to pass the CCNA. Unfortunately, many of the concepts in the exam are still quite recall-intensive, so using exam cram books to boost your ability to recall the facts is a very good idea.
Practice tests - Once you have all the necessary knowledge and facts, as well as a good understanding of the material, you should try out practice tests to ensure that you are able to answer test questions in a simulated test environment. Traditionally, these tests come in a book form where you just complete the questions in a book. These days, there are several computerized test programs where will simulate a real test. These ensure that you have a good feel for the exam before going for the real thing.
Francis writes about networking certification over at SavvyNetCert.
Visit us at SavvyNetCert if you want to know more about what to look out for when purchasingCCNA books or quickly compare between the 4 top books by using our CCNA book comparison