RL Q. Please read if you can play hockey!

i dont know if its in the right section... but anyways. ok... randomness. im the captain of my house at skl, and im organising my team for house hockey matches (yes i know, lame) and im trying to figure out who plays and who does short corners and long corners.... thing is i dont get the difference, or what people are supposed to do. (its six-a-side, including goalie) please help!