Quick link - Electing a Pope
Universi Dominici Gregis - John Paul II - Apostolic Constitution (22 February 1996): Just about anyone who knows me would agree that I’m a nonreligious man, but I thought the actual established procedure for electing the new Bishop of the Church of Rome was very interesting. If you’ve got a spare 30 minutes or so (that’s about how long it took me to read the whole document, excluding the bibliographical footnotes, and also without any cross-referencing), check it out.
Update: OK, I did one bit of cross-referencing. I didn’t know what “simony” was.