I have been canning for over 30 years and have put up thousands and thousands of jars. I have made all the mistakes, and have had some pretty good luck with most. I love it, and even take time off from work now to relax and can.
1I take the rings off the jars as soon as they are cool.. I do NOT store them with rings on. There is too much chance for them to get rusted on and break the seal, or get bumped, or someone re-tighten them and break the seal. They are only meant to keep the lid in place during processing..