Hi damsel02,
Based on my experience, I suggest you that first use "The Princeton Review" to have a general idea about the Exam. I think that this book is great for beginners
Then, try with both
OG 10th and
OG 11th to do the exercises and understand the explanations. Because I am a non native speaker, I practiced all the Verbal Section of each
OG. I also hear that "Manhattan SC Guide" is a really good book. You can find it at
MR-Sentence-Correction-Guide - esnsips., share anything
I hope this helps you. Let me know if you have more doubts

Cheers.