high heat. if you do not have a dishwasher, you need to wash and then boil your jars and set on a towel upside down to dry. this must be done before you make the jelly. the jelly needs to go immediately into the jars when cooked.
it is not hard at all so don't worry. just take your time and read your instruction before you begin. measure out all ingredients first and set aside. this will help a lot.
your friends will surely love this christmas gift. 