Desktop Application

In the bottom left hand corner click the Calendar icon

From the Ribbon menu under the Home tab, at the top of the screen click Add Calendar, then Open Shared Calendar

Enter Staff Calendar into the Name Box and click OK 

You should now see Staff Calendar under your Shared Calendars on the left-hand side.

Web App

On the Office 365 portal click on the waffle icon on the top left and corner

Click All Apps

Select Calendar

Click on Import Calendar

Select From Directory and under Add calendar from directory type in Staff Calendar it should resolve to an email below.  Select this and click on Add.

You should now see the calendar appear for you on the left-hand side.