You can share and view yours and other people's calendars in your domain by:
1. Login to Webmail
2. Click the 'Calendar' Icon on the left side of the page or top of the page if you are no in 'dynamic' mode.
3. Expand the 'Calendar' button at the right of the screen by clicking the '+' sign.
4. Click on the 'Manage Calendars' link.
5. In the new window, in the box below 'Individual Users' section, type in the email address of the person you want to view your calendar and put a 'check' in each of the permission boxes to the right that you want to grant the user.
6. Click the 'Save and Finish' button.
This will overlay your calendar with the new users. This is a great option for a company that has multiple users that need to keep up with everyone Else's calendar events.