While I appreciate your desire to understand human psychology to handle your job pressures better, I am not really sure your reason(s) for focusing on Sigmund Freud.
Sigmund Freud essentially focuses on the concepts & principles of human psychology--not really the choice for practicing HR professionals, who would more of Applied Psychology tips & topics focus.
Coming to your core query, suggest browse the internet--I am sure you will get many books--WITH reviews, that will help you to decide which book you wish to go for.
All the Best.
18th August 2013 From India, Hyderabad