GMAT Strategy

I am ready to purchase some study materials and start getting ready to take the GMAT at the end of April or early May and wanted to know which ones I should purchase. I'm leaning toward the Manhattan GMAT materials as the reviews I have read indicate that they were the most helpful considering the questions on the test but I wanted some opinions. I will be studying by myself 1-2 hours over 3-6 days per week for the next 45-60 days. I will have limited time to study and take practice tests but need to improve my score drastically as my practice exam score was a 500 and I feel I need to get between a 650-700 in order to be admitted to Kenan-Flagler's online MBA program as that is my primary MBA target at this time. If you have any suggestions and/or feedback it would be greatly appreciated.

You should use two types of materials:1. a course on theory and 2. tests/ question banks. When you finish learning the theory, I would strongly recommend that you buy either the Official Guide 13th edition or the access to GMAT Prep software, as these two resources include the real material and are best to test your knowledge before the exam.