Calendar Syncing with Third Party Programs
In your Google calendar, click on “Other Calendars” in the left hand column and select “Add By URL”. Once you seen the pop-up box, enter your calendar feed in the space provided.
Lastly, there is one more step required to have your subscribed calendars show up only if you’re using an iPhone and with a Gmail account. After you’ve completed the steps listed above, you will need to open Safari and navigate to https://www.google.com/calendar/syncselect. Once you’ve logged in, simply check the box next to the the Runs Calendar that will be listed here.
For specific detailed instructions on how to set up your Google Calendar, please see here
For specific detailed instructions on how to set up your iCal, please see here