"Sams Teach Yourself Java 6 in 21 Days" is a comprehensive guide for beginners to learn Java programming in just three weeks. The book covers developing various types of programs, including applications, servlets, and web start applications. It does not require any prior programming experience and offers practical examples to illustrate Java fundamentals. The authors, Rogers Cadenhead and Laura Lemay, provide easy-to-understand lessons with exercises to test knowledge. The book also covers new features of Java 6, such as Java DB and Swing for graphical user interfaces. The goal is to help readers quickly grasp Java programming concepts and develop practical skills in a step-by-step manner.