Bell (the people who make canning jars, lids and supplies) writes the definitive book on canning in my opinion. The USG also puts out pdfs on the subject. I use my Bell book of canning all the time.
Canning without a pressure cooker is appropriate for produce that is naturally acidic because the acid in the produce aids in preventing spoilage, or worse, in the canned material. I use a boiling water bath for canning tomatoes for example. Low acid things, like green beans, stock, soup, meat, etc. will require the pressure cooker.
Enjoy your canning. It is a great skill to have and the ultimate way to preserve the bounty of your harvest, in my opinion, because the goodies will no longer need to take up space in the freezer.
Charles
