If you receive a permissions error when adding a delegate to a calendar in Outlook, please do the following:
1. Close out of local Outlook
2. Go to Start and search for regedit
3. Open regedit and drill down to Computer\HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Preferences
4. In the right window pane, right click in a blank area and select New > DWORD (32-bit) Value
5. Name the new registry key IgnoreSOBError
6. Open up the new registry key and change the value to "1"
7. Close out of regedit, relaunch Outlook, and add delegate to calendar