You may be wondering how you're going to find the time to go deep and study all of the material on the PHR and/or SPHR exams. At this stage of your studying, your daily commitment is to success is critical. Reading every book and absorbing enough to apply to the exam is ideal, but probably not necessary. Instead, consider implementing the following study goals:
Commit to spending 10 or 20 minutes each day outside of your normal study time to research the authors recommended by the Human Resource Certification Institute and their work: Warren Bennis, Charles Handy, Geert Hofstede, Henry Mintzberg, Kenichi Ohmae, Michael Porter, C.K. Prahalad, Edgar Schein, Peter Senge, and Dave Ulrich's Scorecards.
Watch videos online where the authors give lectures, which may be the best way to immerse yourself in what they believed was important about their work.
Create a master document or flashcards of what you believe is most relevant, focusing on themes of leadership development, company culture, metrics, and strategy.
Look for common threads between these authors and articles, and extract what best applies to the exam objectives.
As with so many other facets of these tests, proper planning and development of meaningful study tools can ease your mind and get you ready for exam day.
You're not studying for an MBA, so focus your time on the application of these principles to the exam objectives. Taking a broader view of this material may be interesting, but not purposeful to the one goal that you're focusing on — getting a passing score.
Finally, trust yourself and your talent. What seems overwhelming at first glance will eventually come together in an identifiable shape, and you can see how these pieces fit together in your job as an HR professional. That awareness can help you apply the knowledge to the exam questions, so don't give up if at first it seems fragmented and unconnected. Build the foundation, and the "a-ha" moment will come.