The Little Book of Common Sense Investing, written by John C. Bogle, is a concise guide to passive investing. Bogle, the founder of Vanguard Group, advocates for low-cost index funds as the best long-term investment option. The book explains the benefits of diversification, minimizing fees, and staying the course in the face of market fluctuations. It offers practical advice for investors of all levels and emphasizes the importance of a disciplined approach to investing.