Patrol are led by one Scout called the Patrol Leader. The patrol leader (often called simply the PL) is normally elected by the fellow patrol members. When choosing your patrol leader, you need to consider carefully not just each candidate's popularity, but which Scout will make the best leader. The patrol decides how long the PL remains as PL. For example, it might be six months or one year.
Once you have elected someone to be the PL, you need to help your leader all you can to do the very best job possible. The Patrol Leader's Handbook will also help.