The Princeton Review ACT Prep book is a comprehensive study guide designed to help students prepare for the ACT exam. It includes practice tests, detailed explanations of the test format and content, strategies for tackling each section of the exam, and tips for improving test-taking skills. The book also includes access to online resources, such as additional practice questions and video tutorials. Overall, the Princeton Review ACT Prep book is a valuable resource for students looking to boost their ACT scores and increase their chances of getting into their dream colleges.