Another great post from the Microsoft Online Services team: BPOS-S: How To Configure and View Shared Calendars.
“In our latest BPOS support video we learn how to configure and view shared calendar information. This is a very useful feature that allows co-workers to view your schedule and even manage other users’ calendars on their behalf. This video walks us through how to use your Exchange Online calendar from Outlook to allow for shared calendars. You will also learn how to set calendar sharing permissions, and use OWA to access an Exchange Online calendar share.”