Rules: Rules vary from place to place and situation to situation. You can easily make up your own rules and have everyone agree to them before play actually begins. If you feel more comfortable you might want to look up either the Ivy League rules or the West Coast rules to get some idea of the kinds of rules that are often adhered too.
In terms of the physical stuff that you need to play the game, you just basically need a beer pong table, some cups, (usually the red keg cups) and also some ping pong balls so you can toss them into the cups. And you’ll of course need some beer and beer pong tables too.