The Bhikkhus' Rules -- A Guide for Laypeople: The Theravadin Buddhist Monk's Rules Compiled and Explained, by Bhikkhu Ariyesako (1999; 364k/122pp.)
This book provides a very readable summary of the bhikkhus' (monks') rules, with a particular emphasis on giving laypeople a better understanding of the monks' way of life. Included also are questions-and-answers concerning the proper etiquette for laypeople when in the company of monks (how and when to bow, how to offer food or other requisites, etc.), examples of the particular customs and rules of etiquette that apply at specific Theravada monasteries, and a wealth of other valuable information.