One of the topics that a lot of engineers overlook is to genuinely understand how business works. This is especially important when it comes to information security, because the decisions that we are forced to make so often involve genuine business trade-offs - spending $5 million dollars on a NAC solution may seem like the right thing to do, but only in the context of budgets, risk, and business value. Far too many information security people focus on the "right" solution from a technical perspective without an understanding of the multiple other contexts that are really required to understand exactly what the actual right decision is from the perspective of business.
At the very least, a genuine SSSE understands the political and financial trade-offs that are involved in the implementation of security technology and controls - that requires that they truly understand business from the perspective of the one fundamental question:
How does what we're doing actually translate to the business making more money?
The books I've selected in this section are designed to help give the context to understand all of the important business contexts that will allow you to answer those questions.
What the CEO Wants You to Know - This is a brilliant little book by Ram Charan, a consultant and author of a whole bunch of books on business that are worth reading. This book will give you a high-level overview of things like revenue generation and operational discipline, but he writes in a style that is accessible to everyone.
The Business of Software - A detailed treatment of the way that the software business works. Even if your company isn't in the software business, this one is important for context - it helps you understand the important business processes at work in all businesses, but additionally gives you a whole pile of information on how your vendors are going to work, which is important information when dealing with sales people.
Winning- This brilliant book from former GE CEO Jack Welch could also be called "Business Skills for Dummies". Except that it's written from someone who has actually been there. This one's a "soup-to-nuts" type of investigation of all of the business basics that are going to be important to the development of a career in any department.
Execution - Another book by Ram Charan, this time as co-author with former Honeywell CEO Larry Bossidy. The thing about this book is that it really does talk about the social and performance side of business... it will help you understand why your performance review matters (and why it doesn't really motivate you to do what your VP of HR thinks it should.)