You will read a LOT of stuff about this on the net. I mean to make it as simple as possible.
I do not use kilner jars or muck around with wax seals etc. I just recycle old jars.
sterilization refers to any process that eliminates (removes) or kills (deactivates) all forms of life and other biological agents. In layman terms makes it safe to eat from!
I like my oven hotter as it means even less bad stuff in the jars
heat your oven to gas mark 2
wash your lids and jars in hot soapy water.
rinse them but do not bother to dry.
pop them in the oven until needed ( but must be at least 20 minutes)
when filling be careful not to get any on the rim.
seal and let cool. you will hear a pop as the vacuum inside is made.
anything made like this is fine for 6 months at least.