Extreme Programming: What Is It And How Do You Use It? - by Andrew Powell-Morse. Overview of Extreme Programming, the values and principles behind it and what specific procedures to implement when adopting it.
Extreme Programming; Tips & Advantages - by Ekaterina Novoseltseva. Overview of the rules and practices during the phases of planning, designing, coding, testing, and listening.
XP on One Page - by Bill Wake. One-page poster explaining what Extreme Programming is.