Whether you need to take your GED, GRE, GMAT or any other exam you will need to practice. There are books in the bookstore or library that you can check out which will take you through the exams. There are often free or low cost community programs that will help people study for the GED exam. Usually for graduate exams, however, the courses offered to help you study are rather pricey.
On Test Prep Review you can find FREE practice tests and advice for every test from the GED and SAT to the GMAT and Praxis. This website makes it easy to prepare for your exams without having to spend an arm and a leg on expensive books, or courses. The website is interactive. You take the practice tests online and receive your scores right away. This will give you a sense of what you need to work on. Then there are study guides to help you improve your scores.
This is definitely a great alternative to expensive courses, and long waiting lists at the library.