Hover over Competitions and select Team Setup.
Find your team and select Manage Members.
Find your staff members.
Click the green arrow to add the member to your team.
The member will now appear in the list on the right.
Click in the Roles drop down and tick the box next to the role the staff member holds.
NOTE: the roles must be set up prior to adding member or they won't appear in the list. See How to I add team roles?
When you have finished, click Save in the bottom right corner.