I highly recommend Hélène's AirBnB near Notre Dame. She and her family were very welcoming and helpful before and during our stay. She provided us with explicit directions ahead of time on how to get to her place and even invited us in for dinner. The view was simply amazing and the location was absolutely perfect for both sightseeing and for easy access to public transportation. If I have the good fortune to visit Paris again, I hope to be able to stay at here again.