A PSAT review book is a study guide designed to help students prepare for the PSAT exam. These books typically include practice tests, review of key concepts and skills, strategies for approaching different types of questions, and tips for test day success. Some popular PSAT review books include "The Official SAT Study Guide" by the College Board, "Barron's PSAT/NMSQT" and "Kaplan PSAT/NMSQT Prep". It's important to choose a review book that aligns with your strengths and weaknesses, and to use it consistently to prepare for the exam.