"Amateur Radio Contesting FAQ"  (Andrew Roos ZS1AN)

"Contest Rules For The 21st Century"  (NCJ May/June 2009) (K5RC, W5FU)

"Contesting"  (Wikipedia)

"Contesting for Non-Hams"  (N6XI)

"HF Contesting - Good Practices, Interpretations and Suggestions"  (This White Paper by the ARRL Contest Advisory Committee (CAC) does a great job explaining some of the subtleties of contesting, particularly what is considered proper and improper, even if not explicitly spelled out by the rules.  Whether you are an experienced contester, or new to the game, this paper is well worth the time it takes to read it.)

"The Joy of Contesting"  (QST January 2008) (K6RB)