Free WWII Canning guide ebook
Every Step in Canning The cold pack method – by Grace Viall Gray (this link via Project Gutenberg, in various formats or read online)
Every Step in Canning by Grace Viall Gray (free via Amazon download, and there's a paperback edition that was re-released in 2004 as part of a Prepper Archeology series)
A review from Amazon:
Looking at the way things are going, we're stocking up on hard-copy canning, food preservation, and gardening reference material. We stumbled over this book during our literary search, and were quite delighted to purchase, receive, and peruse it. We plan on putting it to some good use!