Exempt/non exempt again

Mimi

We are in the midst of reclassifying and "cleaning up" our job descriptions, exempt, non-exempt status, et cet and I need help with salaried, non-exempt employees who are on commission - some total commission, some base + commission. What does the law require as to overtime pay for total commission and base + commission and are they required to punch a time card? These are all route drivers. Would appreciate anyone's input on this.