We think that the Princeton Review's GMAT book is not as thorough as ARCO's, however, it includes an excellent CD-ROM with exercises and practice tests. Several subject specific guides are noteworthy. The Princeton Review publishes a spectacular GMAT verbal review text and ARCO publishes a great GMAT writing book that includes examples of all essay questions one might face. Any course must include The ETS Official Guide to the GMAT . The book includes several thousand actual GMAT questions that the students can use for practice, although their explanatory answers are almost laughably complex.
Internet now offers a variety of teaching options.
Regretfully, most are subscription based. Both pages offer explanations of the types of tests and complete practice tests with explanations. The ETS GMAT site also has a downloadable file with all the possible essay questions and all information needed to register for the exam. While there is no substitute for the significant study the GMAT requires, a proper GMAT course has the potential to boost a student from a mediocre score, to an exceptional one. Teachers just need to point their students in the right direction.