How to turn off iCal email notifications

I just synced my google calender with my iCal through iCloud and now I keep getting notifications about events. The events are from another family members comuter and now they are emailed from their computer to mine. I don't know how to turn this off and it is really annoying. I am also getting pop up alerts on my iPod touch 2nd generation and I can't figure out how to turn those off either. Help Please!!!!