For my foray into making Cherry Jam, I read David Le Bovitz's "No Recipe Cherry Jam" and used the essential ingredients of cherries, sugar and lemon juice but varied the amounts to my taste. Cherries contain small amounts of pectin, so lemons are used to help give the jam a jelly like consistency. I am using ordinary sugar without pectin and it worked just as well.
If you would like more information on how to sterilise a jar or some other jam making basics this video on Strawberry Jam making at the BBC is a good place to start.
After all that cherry picking, this Cherry Fizz is a drink I make for myself as a little treat to cool off....!