Are there any penalties for canceling or changing a reservation
This depends on the hotel in which you have made the reservation. Some hotel keep a percentage of your booking deposit as penalty for cancellation while some others will refund you the entire amount. But in generally most of the hotels require cancellation before 72 hours in order to refund you your deposit. While making your hotel reservation you need to read their cancellation policy properly.
If you really have an emergency then you can cancel the reservation without any charges if it is done early. If you have missed the flight or cancelled the trip at the last moment then you may have to pay a few percentage of the booking for it.
For more information about canceling the reservation online you can visit http://reservations.onlyinsanfrancisco.com/797_help.html
