-- Use reliable sources for your recipes, such as:
National Center for Home Food Preservation - this site includes the entire book So Easy to Preserve, and lots, lots more. This is a HUGE resource.
The Ball Blue Book, and the new book The Complete Book of Home Preserving
USDA's Complete Guide to Home Canning - we were given this printed guide at our class; I think they told us that it too is available online in its entirety at the NCHFP site above.
Cooperative Extension Service recipes
-- Half gallon jars should only be used for acid fruit juices (apple and grape, NOT tomato juice)
-- If you water bath for less than 10 minutes, you should sterilize the jars in boiling water for 10 minutes before filling
-- Using a rack is extremely important in both types of canners (BWB and pressure canner); you need water to circulate under the jars during processing. Do not use a towel on the bottom of the canner instead of a rack. You can substitute jar rings, or a cake cooling rack in a water bath canner, or use the rack from your pressure canner in your BWB canner.
-- Do not leave salt out of pickle recipes, it will make your pickles soft. You can omit the salt out of canned vegetables if you wish. Add salt to veggies after filling your jars.
-- When you simmer the lids ("flats") in hot water before putting them on your jars, alternate them (one right side up, the next upside down) so they won't stick together.
-- If you don't have one of those magnetic jar lid thingies, you can make one with a magnet, a dowel rod, and Gorilla glue.
-- To find your altitude, go to altitude at the National Center for Home Food Preservation. It will take you to a USGA site with topographical maps.
-- To use a pressure cooker as a pressure canner, it must hold at least four quart-size jars. Anything smaller is too small to use as a canner.
-- To use a stockpot or other tall pot as a boiling water bath canner, it must be tall enough for the rack, the jars, and another 1-2" of water over the top of the jars, and then enough space above that so the water doesn't boil over. The pot must also have a lid.
-- How to store a pressure canner: Make sure the pot is dry. Add some wadded up newspaper or paper towels to absorb any moisture that's left. Put the lid inside a brown paper bag, then set it upside down on top of the canner. Keep the manual inside the pot.
-- I was measuring headspace incorrectly. Measure from the top of the jar. The point at which the threads begin is 1/4"; the end of the threads is 1/2"; there is a mark/ridge you can feel with your fingernail under the threads that is 1" from the top. No need for a ruler!
If you have any other tips, please leave a comment. Thanks!