A Great Companion to Your ACSM Study Material!

I would definitely recommend that you supplement you studying with the following book:

Exercise Prescription: A Case Study Approach to the ACSM's Guidelines, second edition

This book will give you a good idea of how to approach exercise prescription:

-2 cautions about this book:

1. ACSM's risk stratifications have changed as of 2009.  Therefore, you have skip the case studies on these sections.  I'm sure the 3rd edition, when it comes out, will have the updated risk stratification criteria.
2. You will not need to know the case studies for the metabolic equations as those are used only for the ACSM HFS exam