Q&A for How to Sterilize Bottles and Jars for Canning

If they are glass or metal, the best way is to place them in boiling water.

No. Just be sure to avoid sudden changes in temperature. As long as you heat gradually and cool slowly, your glass will not break.

If the home canning is done properly (by following established standard practices as described in USDA publications or Ball Blue Book, for example), the food will last for many years without "going bad" in the sense of becoming unsafe to eat. It will, however, deteriorate in quality during that time. This depends to some extent on how it is stored, too. Canned peaches that are kept in the bright light of a windowsill will darken noticeably within months; it will develop off flavors as well. Stored in a cool dark place, a jar of peaches from the same batch could still taste fresh after a couple of years.

Plastic jars can be used if you're able to sterilize them. Plastic doesn't hold up to heat as well as glass, so you're better off sticking with glass to stay safe.

You need to fill the pot to 1” over the rims of the jars. Putting water in while filling will prevent extra shifting during the fill.