Only those with Exchange accounts will be able to set sharing as noted here. Please check with your deparment's IT support group if you are not sure whether Outlook has been configured for an Exchange account.
Allow others to view your Calendar or Inbox (Delegating)
Within Outlook, select Tools - Options from the upper left menu.
Select the Delegates tab, then the Add button.
Begin typing the name of the person you want to have access to your Calendar in the upper left field. When it is highlighted in the list in the center of the window, select the Add button towards the bottom left. The person's name will appear underlined in the Add Users field.
The Global Address List must be selected in the "Show Names from the:" drop down menu in the upper right of this window.
If you do not see someone in this list, they may have "hidden" their account on the Exchange server, or may not have an account. Please contact the individual to find out.
Repeat Step 3 if you would like to add more people, then click OK when finished.
Select your desired permissions for those who will be sharing any of your items in Outlook. If you will be sharing your Calendar or Inbox so another person can schedule meetings and reply to emails, select Editor from the drop down menu for either or both of these items.
To notify anyone that you've delegated them for Outlook, check off the Automatically send a message to delegate summarizing these permissions checkbox to notify them via email. Select the OK button.
If you would like to change the permissions of any individuals that you have shared Outlook with, highlight their name in the middle field of the Options - Delegates window and click the Permissions button on the right to edit their settings. You can also remove people by highlighting their name and selecting the Remove button.
Select Apply and OK when you have finished delegating permissions for your Outlook.
Open a Shared Outlook Calendar
Within Outlook, select File - Open - Other User's Folder from the upper left menu.
Select Calendar from the Folder type drop down menu, then type in the person's name in the field above Folder type or click on the Name button to search.
NOTE: You will only be able to open the Calendar of someone who has already made you a delegate.
The other person's Calendar will be displayed with their name in the upper left corner of the view. If the person has set some items as Private, you will not be able to read or access that item by default.
The lower left corner of your Outlook Calendar view will list all Calendars you have opened. Check or de-check the box next to the person's name to view or hide their Calendar. Your own Calendar will be listed under the My Calendars heading.