Several companies publish GMAT study guides. The most widely recognized and used GMAT study guide is the "Official GMAT Study Guide Series," published by the Graduate Management Admission Council (GMAC). Official GMAT Study Guide books contain advice for every section of the GMAT, and give sample questions for both verbal and mathematical questions. The official GMAC guides are available in print and electronic form, and are available for purchase at the GMAC website.
Practice tests are valuable tools for GMAT test-takers. Practice tests allow students to take a previously administered GMAT, giving you the opportunity to master GMAT before you take it. GMAT practice tests are available from a number of sources. The GMAC website offers GMAT Test Preparation Software, which provides two complete GMAT tests as well as a number of bonus questions. A number of unofficial websites offer smaller inventories of practice questions for each GMAT section.
There are several websites that offer free, online GMAT study advice. These sites are not official, GMAC-approved sources, but some of them are well regarded by individuals in the standardized testing field. Prep sites like Princeton Review, Veritas Prep, and Kaplan publish some of their course information online, and this information can be used to guide your study sessions. Some individual students have also published GMAT websites with study hints and tips.
There are some companies that offer comprehensive GMAT home study courses. These courses usually consist of a DVD set, a textbook, and a notebook. These courses tend to be fairly expensive (in the $500 range), but are more comprehensive than conventional GMAT study materials. The only company currently offering a comprehensive GMAT home study course is "The GMAT Coach."
GMAT questions are not esoteric. The GMAT evaluates similar basic verbal and mathematical reasoning skills similar to those used in college language and science courses. Study materials that are not specifically designed for the GMAT, such as English grammar books, dictionaries, and math textbooks, can be very helpful when studying for the GMAT. English books should cover grammar, reading comprehension, and critical reasoning. Math books should cover arithmetic, algebra, and geometry.