Having worked with many students who have successfully achieved high scores in the SAT over the years, we have shortlisted the following as the most useful. We strongly recommend that you buy at least two books to prepare for the SAT.
Firstly, you should get an official guide from the College Board. The book will contain actual questions from prior SAT exams. There is a significant difference between the official questions you will be asked on the exam and the practice questions contained in all other books. You need a College Board publication to familiarize yourself with the quality of questions you will encounter on the SAT.
Secondly, you should consider buying at least one of the "unofficial" guides reviewed below. Knowing the timeproven testtaking strategies would help to improve your score. The better unofficial guides contain many such strategies, as well as explanations and timesaving techniques to answer questions.
You will greatly increase your chances of receiving a higher test score if you prepare yourself with SAT testtaking strategies and knowledge of actual questions from previous exams.
For SAT from March 2016 and after. 

The Official SAT Study Guide, 2016 Edition is made by the test makers  The College Board  and so is the most accurate out of all the other SAT prep books and includes real SAT questions from previous tests. It has 4 fulllength SAT practice tests to help you get comfortable with the SAT format and timed testing conditions.  
For SAT in Jan 2016 or before, use the study guides below. 

The Official SAT Study Guide, Second Edition is made by the test makers  The College Board  and so is the most accurate out of all the other SAT prep books and includes real SAT questions from previous tests. With over 1000 pages and more than 20 chapters, it includes 10 fulllength SAT practice tests to help you get comfortable with the SAT format and timed testing conditions.  
Cracking the SAT features great strategies, and include things you need to know to ace the test. It includes 5 fulllength practices tests and exclusive free access to further review online. The practice questions has detailed answers and explanations for every question. This book will keep your attention and is easy to read while providing the necessary lessons, strategies, and practice tests. But if you want a book that's more serious and down to business, you might prefer one of the other books.  
A very good guide by Kaplan, It gives you strategies that take advantage of the test structure. The math section include the basic math foundation and strategies on how to save you time and to avoid some the math traps. It provides 5 fulllength SAT practice exams and gives you free access to many more online tests at Kaplan's website.  
Gruber's Complete SAT Guide is a complete guide to succeeding on the SAT. If you need an SAT prep book that will teach you from the basics, this is the book for you. It has wellexplained, comprehensive lessons on every topic that is covered on the SAT, plenty of sample SAT practice problems throughout, and 5 fulllength SAT practice tests with detailed solutions.  
Advanced prep, for advanced students. This book features the toughest questions, and the best strategies for you if you are aiming for a 2400. 
Besides these study guides, you may want to check our resources for SAT preparation. If you work better with some personal coaching, you can also find tutors for SAT math, SAT reading or SAT writing.