We canned about twenty pounds of tomatoes and ended up with twenty pints of tomato sauce.
The first step is to bring a large pot of water up to boiling. Cut an X in the bottom of the tomatoes before tossing them in the boiling water to remove the skins. Just a couple of minutes is all it takes.
Remove the tomatoes and set them in a colander to cool off for a few minutes so that you can handle them. When they are cool enough the skins will be easy to remove.
While they are boiling they need to be stirred often. The tomato sauce will reduce quite a bit and become more concentrated. How much you reduce them is up to you. The more you reduce them the more the depth of flavor they'll have.
After the sauce is reduced you will probably want to remove any large chunks and throw them in a blender and then add them back into the large pot.
The jars and lids need to be given a hot water bath before canning. After they are removed from the water, fill each of the jars, not quite filling them completely.
Place the lids on but don't tighten them all the way. Depending on the size of your pot you can process eight to twelve jars at a time.
Submerge the jars into a pot of boiling water and be sure they are covered at least one inch by water. Let them sit for about five minutes.
After that remove them and let them sit out. In a few minutes you will start to hear the lids popping. This tells you that the vacuum has formed in the jar.
This process doesn't take very long and if you are sitting around on a weekend you can do this in a couple of hours and drink beer at the same time.
No matter what, your own canned tomato sauce tastes better than the store bought stuff. Tomato sauce is the base of spaghetti, chili, brunswick stew, chicken cacciatore, tortilla soup, etc.