Rules of a relay race?

I teach 2nd grade and I have a group of 19 students. We want to do a relay race with another class that has the same number of students. What are the rules and ideas of this game?|||you set a person so far apart.if your running 4oo then you take for 4 person a hundred miles apart have a stick or roll up newspaper, start and hand off to the next person. the next person can run Little ways before the hand off. it has to be a clean hand off, if it drops to the ground it was slow down the the runner that had the paper has to pick it up and then hand it to the next runner, its to learn people how to work together. and it learns Carnation.