It would be very advantageous to get the Ball Blue Book of Preserving (less than $10) which is the Bible for food preserving, not just canning. Great for everyone, with instructions and recipes.
Regarding tomatoes, are you aware that modern recipes require the addition of citric acid/lemon juice because many tomato hybrids these years are not as acidic?
Not only has technology and our knowledge of bacteria, molds, etc., changed, but the very foods we preserve have changed. One needs to keep up to date to be safe.
Support bacteria. It's the only culture some people have.