If you're running 10.8.1 you don't have ical. It's now Calendar. If you still have ical, then something else is wrong. Also, do software updates. You should be running 10.8.2
If you want your calendars in icloud for the purpose of syncing devices, you would go into system preferences >> icloud. Sign in with the same apple id that you use on the devices you'd like to sync with. Check off calendars. The rest should be automatic.