1.  Open Outlook and right mouse click on Calendar.
2.  Click on the Properties tab.
3.  Click on the Permissions tab.
4.  Click Add to open the Active Directory to select the user you want to have access to your 
     calendar.  Continue selecting individuals or click OK to be brought back to the
     Permissions tab.
5.  Click on each individual and determine their access level.  Once you are finished,
     click Apply and then OK.