how to transfer outlook 2011 calendar to iCloud calendar?

I am using Outlook 2011 for Mac and can't seem to move the calendar items to the iCloud calendar. In addition, my iCal calendar doesn't even resemble either the iCloud calendar (virtually empty) or the Outlook calendar. How do I sync them all together? Also, I have over 3,000 duplicate calendar entries for some events and need to erase the duplicates.