This document shows you how to share one of your calendars in Outlook 2011. This will allow another user to either read, create or modify your calendar, depending on what permissions you give them.
Select Calendar in the navigation pane on the left hand side.
Open Sharing Permissions
Right-click (or ctrl-click) on the calendar that you want to share and select Sharing Permissions.
Click Add User. In field at the top of the Select Users dialog box, type in the name of the user, then click Find. Select the correct user, then click OK.
Now that the user is in your permissions for the calendar, you can give them whatever permissions by either using the preselected permissions level or giving them your own custom permissions. After you are done giving permissions press OK.
Users that you selected will be able to view your calendar once they tell their Exchange mail client they want to.