When a Google Calendar has been shared with you an email will arrive in your inbox notifying you of this new calendar.
Open your Google Calendar and the new Calendar will appear in the "Other calendars" list.
The calendar will automatically be assigned a color by which you will be able to recognize appointments and events created in that particular calendar.
You can change this color by placing your mouse over the calendar name and then clicking the down arrow that appears to the right of the calendar name. Click on one of the other colors.
If you would prefer to not see the calendar, click on it once. The color will disappear from the box on the left and any appointments or events in that calendar will no longer be visible in your calendar.
You can share appointments or events from one calendar to another by clicking on the appointment/event and toward the top of the screen click the arrow to the right of "More Actions".
Select "Copy To ...your calendar"
You will then see the appointment/event twice on your calendar. If you go into the appointment / event specific to your calendar you can make changes such as adding a reminder or setting the appointment / event as busy on your calendar.
There will be times when you see the appointment / event in your personal calendar without first sharing it. This is because you were individually invited to that particular appointment / event. This is important when you are a requested/required participant and the time or location changes. You will see the change in your calendar as well.
Google Calendar >