Hi, as I know the best anatomical book is made by Frank H. Netter; he painted beautiful tables of nearly every part of the body, maybe this will help you. The 'Netter' is also available online I think.
For to understanding the anatomy of prostate gland and associated organs, its environment Gray's Anatomy is too good. Additionally Netter's atlas of human anatomy and McMinn's colour atlas of human anatomy will help you better understanding of Morphology and and its related structures.