You can add this shared calendar to your computer by following the below steps:
For Office 2007
Open Outlook, Click Calendar > Calendar> Open a Shared Calendar > Click Name… > Find the contact whose calendar you want to add, and double-click on it. Click OK > Click OK. This calendar will appear under your shared calendars.
For Office 2010
In Outlook, Click on Calendar > Right Click on Shared Calendars > Select Add Calendar > select From Address Book > Find the contact whose calendar you want to add, and double-click on it, and click OK. This calendar will now show up under your shared calendars.