In order to add Additional Crews to your Crews List you will select the "Booked Jobs Calendar" (as shown below).
Once you can see the calendar you will select a day from it.
You will see the option to "Add Crew" at the top under the date (as shown below).
You will then need to create a name for each Crew added.
NOTE: Regardless of the day you select to Add the Crew to it will show on every day after being added into the system.