If you dropped in hoping I'd have a visually stunning and technically engaging treatise discussing the finer points of canning tomatoes I am deeply sorry that I (or rather blogger, or maybe my computer) will be letting you down. It was here and then it was not and I don't have the time, what with tomorrow's embarking on a nine-plus-hour car trip with the kids and all, to recreate the entire post.
And so not to make this all a complete loss I will share the following:
1) The USDA no longer recommends water bath canning for tomatoes on the grounds that many of the newer varieties have been bred to be much lower in acid than their love apple ancestors. I, myself, continue to do so although of course I cannot and will not suggest to you, my bloggy friend, that it's a good idea. I plant primarily Amish Paste and Roma varieties and since these are considered heirloom (i.e., pre-technological intervention in tomato breeding) I throw caution to the wind.
2) However, I do add salt and lemon juice to each jar thereby hopefully bringing yet more safety to my devil-may-care approach to the whole affair.
3) Because garden tomatoes tend to come in two or three at a time (at least in my garden), it can be tricky to have enough at any given time to actually can anything. I can almost everything in half-pints and even these smallish jars might require 8 to 12 (or more) Romas to fill. My somewhat unorthodox approach is to scald, peel, seed and dice the fruits as they are ready and freeze them in a large container until I have enough to actually make it worthwhile to get out the kettle. Not only is this tidier (good for when your house is on the market, for example) and more efficient, but the outcome is no less tasty than if you bought a bushel at the farmer's market and canned them all at once.
4) Although I am pretty picky about using only absolutely ripe tomatoes, I have no problem with cutting off a bad spot and scalding the remainder. Some people get all antsy about it and say that you're watering down the flavor if you scald cut tomatoes but I figure mine are going into soups, stews, and chillies anyway so it's not like that's a big deal. I'm totally onboard with seeking prime tomato taste for your tomato sandwiches or your tomato-mozzerella salads, but no one is going to get me all flipped out about tomatoes that will end up having a quarter cup of chili powder, a pound of beans and a cut-up steak all mixed up with them.
5) Scalding is easy and I recommend that you sever ties immediately with anyone who tries to scare you into thinking otherwise. Bring a large pot of water to boil, add the tomatoes a couple at a time and simmer away until their skins split and/or start to look kind of wrinkly. Remove them with a slotted spoon to a collander to drain and cool. When they're good to handle (that is, you won't burn yourself), peel away the skin - it should slip right off - cut away the ends, slip the seeds out with your hands or a spoon and dice right into a bowl. I don't sweat getting all the pieces uniform in size, but if that's important to you then by all means sweat it. If I have enough to can, then I do. Otherwise, the pieces are dumped into a large freezer container until I have enough to can (see above).
6) I tend not to get fancy with these and don't add herbs, onions, garlic or anything else to make them "recipe ready" as they say in the packaged food biz. Such ammendments really are more suited to pressure canning and, despite my apparent cavalier attitude toward the USDA's recommendations for tomatoes, including them runs counter to my risk-management philosophy.
And that's it. In a good year I have enough tomatoes to see us nearly through the winter. In a not-so-good year I have to start buying commercially canned tomatoes sometime in February or March. Despite our slow start to the season, this is looking like a better than average tomato year; we eat our fill with plenty left over for the no-fresh-tomato months.