1. Go to Administration → Jobs.
2. Click + Add New button.
2. Enter the Job Type name, select the default checklist, and add a default description.
Once done with the configurations, click Save to proceed and when you create a job, you'll already able to select the job type that you've created.
Note: You can also assign a default color for the job type as well as select a Custom Form which you can set as a required form before First Check In or after Job Completion.
To learn more about adding a default Custom Form per job type, please see How to automate a Custom Form at Job Check-in or at Job Completion user guide.