I read Kurlansky's Cod, too, and these books are packed with information. He's a good nonfiction writer, on the whole, but limiting the book to a single topic does result in some repetition.
Don't miss: McIllhenny's adventures in the salt business before he got his crazy idea about hot pepper sauce and Gandhi's salt campaign as the flash point for Indian independence.
If you're writing fantasy, it's something to think about. Salting and pickling were some of the leading ways to preserve food for thousands of years, so salt's production needed to be constant and it was usually taxed because everybody needed it. Although rock salt can be easier to get, sea salt has always been more popular. Producing sea salt takes up a lot of space and requires a lot of cheap fuel if you're not in a hot climate. Mining salt is full of its own problems.
If you're interested in how to set up salt production in your fantasy world, this is a must read. Plenty of detail about evaporation ponds, pan boiling, working brine wells, removing impurities, preserving fish and meats, pickling, and systems of taxation which led to public outrage.
I'm currently writing science fiction, but it's not exactly economical to create sodium chloride entirely from chemical reactions. Or is it? Is there rock salt out in the asteroids?