Using a calendar out on your SharePoint team site has a few
advantages:

• Everyone on your team can access it and add
  appointments.
• Security is managed through SharePoint.
• If the calendar’s creator leaves the company,
  the calendar still exists. This is an advantage over sharing calendars in
  Outlook.

However, because I use Outlook to manage most of my
appointments, I find that going out to a separate site is a big drawback. Do I really
have to spend my day navigating among my various calendars? It turns out that I
don’t – I can manage everything directly from Outlook.

• Go to the SharePoint calendar you’d like to
  sync.
• In the ribbon, click Calendar | Connect & Export | Connect to Outlook.

• You’ll have to click Allow and Yes through
  the 2 security dialogs.
• You should see the SharePoint calendar available
  now in Outlook.

• If you click the left arrow on the tab for the 2^nd
  calendar, you can view the 2 calendars in an overlay.

This ability to view the SharePoint calendar within Outlook
also has the following benefits:

• The Outlook calendar will automatically sync
  from SharePoint.
• Changes and additions you make to the calendar
  in Outlook will be reflected in SharePoint.
• You can toggle the calendar from your active
  view by checking/uncheck the corresponding box on the left.