Foods can be safely preserved at home in a boiling-water canner or a pressure canner. Boiling-water canners are used for acidic foods such as jams, jellies, fruits, pickles, and tomatoes. Pressure canners are necessary for safely preserving non-pickled vegetables and meats.
If you are just learning about canning, start with a boiling-water canner. They are less expensive and easier to operate than pressure canners, and will give you a good introduction to canning food. You can find boiling-water canners and basic canning supplies at most hardware stores. Be sure your canner comes with a rack, which helps keep jars in place during processing and helps elevate and lower jars.
Purchase glass canning jars and 2-piece lids in the sizes you need. Quart jars are best for canning tomatoes, peaches, and other large foods. Pint and half-pint jars are best for pickles and jams. Canning jars and lid rings may be re-used until damaged, but the flat lids can be used for processing only once to ensure an adequate seal. Basic canning instructions are included with new packages of canning jars and lids.
A few good books with lots of recipes for canned foods include the Ball Blue Book of Preserving, The Big Book of Preserving the Harvest, by Carol W. Costenbader, and Putting Food By, by Janet Greene, Ruth Hertzberg, and Beatrice Vaughan.
A canning funnel and a jar lifter are essential tools you'll need during the canning process. With all of the products above, you're ready to start canning.