I think you want to "share" your calendars with one another. In the Calendar app on your Mac, click Calendars in the upper left, then right-click (or control-click) the calendar you want to share to reveal the menu items for managing the sharing status of your calendars. Same menu items are also under Edit on the Calendar menu bar when a calendar is selected.
In ML, be aware that calendar changes are announced in Notification Center (can be useful, but unexpected, to see them).