Be sure you give yourself enough time to prepare for a standardized test. Both the GRE and GMAT are now administered through computer adaptive testing. The following websites will provide you will specific information on test dates and content of testing materials. Scores are generally valid for five years with the exception of the LSAT (3 years). If you are sure you will be applying for a graduate degree in the near future, you may want to consider taking the standardized test in your Senior year. This way you will have part of the application process completed. You should take summer or early fall tests if you plan to apply to graduate school in the upcoming year.