Need advice on which MFA guide to buy?

I was at B&N the other day looking at study guides, and I became overwhelmed by the sheer amount to choose from. I’m not sure which one is the best, or if I even need one. Princeton-Review has an online program one can subscribe to, but I’m not convinced that it is the best option either. Do I need an MFA guide and a GRE prep guide? I would like to get a masters or MFA in creative writing, and a doctorate in something related. Now, before you tell me that either one is a bad idea to undertake, please understand that when I set out to change what I was doing in my life, part of that commitment was to go back to school and to take it as far as I could go. I decided that I wasn’t going to choose the easy route in a life decision anymore, so this is a part of it. Advice? Ideas? Thank you for your time.