On Outlook go to Contacts, on the left hand side look for the calender you are going to share.
1. On Intel based Mac's with Right-Click mouse Right-Click on the Contacts and select 'Sharing Permissions' on Mac's without Right'Click Mouse use Ctrl + Click
2. On the 'Permissions' screen you can select whom you wish to share your contacts with and also the 'Permissions Level' you wish to give them.
3. Make your selections and simply click 'OK' to save the changes.