To enter the max number of hours / week that your employees can work, please visit the "Employees" page.
Select the employee that you would like to set up their "Max Hours/Week"
Below of the "Hourly Rate" field, you can enter the max # of hours per week.
Click on the "Save" button.
Now next time you would like to auto schedule your employees, it will take into consideration that this employee would not surpass the max # of hours that you've entered.