The essential handbook of internal auditing covers topics like corporate governance, managing risk, internal controls, the role of internal audit, professionalism, and the audit approach. It discusses the reasoning behind the book, the IIA standards, and how to navigate it. The book emphasizes the importance of ethics, accountability, and risk management in auditing practices. It also highlights the need for controls, audit independence, and continuous improvement in the audit profession. The handbook serves as a valuable tool for development and understanding the evolving field of internal auditing.