Click on Click to add slots. This opens up a list of job groups.
Drag a job over the calendar. VSys will get the start date and time from where you "drop" the job, and show you the Add job slot dialog.
Assigning someone to a job slot
Click on Add people (upper-left corner). Find someone, then drag them onto the job slot. Or:
Right-click on a slot and select Assign a volunteer. Select Search to find a specific person by name, e-mail, etc., then click on Select. Or choose Automatically find someone to assign, then drag the person onto the job slot.
Creating an assignment
Click on the Add people link (upper-left corner). Find someone, then drag them onto the calendar.
Drop them on a slot to add to a specific job slot, or
Drop onto an assignment to make an assignment similar to the existing one, or
Drop onto the calendar (empty space).
If dropped onto anything other than a slot, VSys will prompt you for One-time assignment or Recurring assignment.