To add a shared Calendar to Outlook please go into the calendar page in Outlook (circled in Orange below) Then click on the Add calendar option 

Then on the next screen check Add from Directory on the left and pick your account (which will be your name) from the drop-down box. Then search for the shared calendar name provided but IT Support Then pick what area you would like to add it to, normally this will be "People's calendars"

Thius is an example as myself adding the IT Support Calendar to my list of people's calendars