2- Under Permissions tab, click on Add… button and choose the groups or users that you want to give them access to your calendar. Once the users are added to the list, click on the user to highlight it and under permissions, check the Folder Visible checkbox. This permission will just allow the selected user to see the mailbox and not it’s CONTENT! Click on Apply once finished.
3- Now we need to set the security on the Calendar that we would like to share. Now, in Outlook 2003, click on Calendar on the left pane.
4- You should now see all of your calendars in the list. Right click the custom calendar and choose Properties. In this example the calendars name is Custom Calendar.
5- Under Permissions tab, you should see the user that we gave permissions to see the folders earlier. Now select the desired user by highlighting its name and choose a Permission Level under Permissions section. In this example, I’m giving Author rights. Once the permissions are set, click on Apply and OK to close the window. For more information on these permissions please refer the link here. http://office.microsoft.com/en-us/outlook-help/outlook-folder-permissions-HP005242287.aspx
Now that all the permissions are set correctly, users that require access to your Calendar can open your custom calendar in their Microsoft Outlook. Follow the instructions below in order to open a custom shared calendar.
Open a Custom Shared Calendar in Outlook
1- Open your Microsoft Outlook 2003. Right click on your Mailbox and choose Properties for Mailbox…
2- Under General tab, click on Advanced… button.
3- You should now see the dialog box for Microsoft Exchange Server. Under Advanced tab, you will see the Mailboxes section.
Click on Add… button and type in the user name that you want to access its calendar and click OK.
1- Click OK until all the other dialog boxes are closed.
2- You can now click on Calendar on the left pane of your Outlook, and you should see the shared calendar as well as all of your personal calendars. The actions that you can make on any calendar depends on the permissions that you were given.
While all these procedures were written based on Microsoft Outlook 2003, they can also be applied to a Microsoft Outlook 2007 or 2010 as the procedures are close enough to use a single guide.