Due Diligence: How to Research a Stock is a straightforward guide to the process of effectively researching potential stock market opportunities. The method featured in this book is the one developed and used by the author over many years of studying companies. He describes three stages-quick due diligence, medium due diligence, and full due diligence-and explains the requirements and estimated amount of time for each one. The book covers what questions to ask at each stage of the process, how to use various resources, such as SEC Filings, and which websites are the most helpful and why. The author also explains how to find and interview the subject company's customers, suppliers, and managers. Due Diligence: How to Research a Stock provides readers with the knowledge and background needed to investigate any business entity in order to improve one's chances of success in stock market investing.