I started with sterilizing my jars;
Wash jars with dish soap and rinse well with hot water.
Preheat oven to 120C and place jars in the over for 20 mins.
I add the lids 5 mins before the end otherwise the rubber can burn.
Next I washed the tomatoes and boiled on the stove until the skin splits and is coming away from the flesh.
Once tomatoes are cool enough to touch peel the skin off.
You can also de-seed if you like but I didn't.
At this point you can freeze them whole or puree them in a blender before freezing.
I added some fresh herbs to mine and heated so that they were ready as a sauce base.
Defrost completely before using.