First, all you ever really need to know: DePaul Rules
Second, should you be found to endure a NCDA style tournament: NCDA Rules
Third, sometimes we mix it up with some alternative forms of the classic ruleset:
Continuous - Free-for-all dodgeball.
Coneball - A beloved favorite that ruins lives.
Jailbreak - Sink a basket when the nets are down and your whole jail is back in.
Medic/Sexy Nurse - When a person gets hit, they drop and the team's Medic must save them to get them back in.
VIP - One unknown player is the VIP. Knock out the other team's VIP for instawin.
Zombie - One player is the lumbering undead. Watch out for infection, watch out for headshots.
And a legacy all the way from 2006 - Midwest Dodgeball Rules [revision 4] - they may not be valid anymore, but its like Latin. People will always call back to it, even though there aren't any native speakers to learn from.