The Commission Setup has many aspects and it depends on an organization whether if you want to have all of them enabled for you. Below are the various aspects of it
Create commission plans: Every sales agent will be assigned a commision plan and this explains how to create those plans
Create sales agents: This explains how to create sales agents
Create sales agent groups: This explains how to create sales agents groups and assigns the sales agents to these groups
Create a Commission quota: This will help you setup a quota where sales agents will be required meet the quota of commission.
Commissions applied to Sales Agent: This explains how to apply a commission to a sales agent