You can halve or chop up the tomatoes prior to putting them in the jar. You could even mash them up with a potato masher. We prefer to can them whole as it is quicker and easier, you can always chop them up when you use them.

Some people core their tomatoes first. You can do this if you wish. It will make it easier to skin them. You can also cut and "X" in the bottom of the tomato before putting it in the boiling water. This helps skinning as well.

It is also very easy to freeze tomatoes. You can follow the steps above, leave out the lemon juice, put the tomatoes, skinned or not, whole or chopped, in plastic bags, remove as much air as possible and freeze them.