This area is is located on either side of your rib cage above your obliques and below your lats. More specifically from the upper 8th or 9th ribs of your chest and inserts along the scapula. It is responsible for the protraction of the scapula, basically called the boxers muscle as it allows the scapula to pull forward in the motion of a punch. There are not many specific direct exercises to target the serratus, but it does act as a secondy muscles for many exercises involving the back, shoukder, chest and abdominal muscles.