You can find Google's official instructions for sharing a Google calendar here: https://support.google.com/calendar/answer/37083

The steps are as follows:

1. Go to https://calendar.google.com and click on the Settings icon at the top right and then on the Settings submenu item.

2. Scroll down to the Settings for my calendars section and click on the name of the calendar you wish to share. In this example we're sharing a calendar called Club Events.

3. In the settings for that calendar go to the Access permissions section and click on the box next to Make available to public.

4. Finally, scroll down to the section Integrate calendar and copy thelink labeled Public address in iCal format:

That's the address you would then enter into the events calendar settings or any other application you want to access the calendar from (like Outlook).