I like Adams's _The Negative_.

The advantage of developing by time and temperature using a densitometer, is that it's something you can learn relatively quickly from a book.

DBI can get you the same results, but it helps if you have someone who can look at your negs so that you can learn what a good negative should look like.

In either case, it's important to be able to look at fine prints in galleries or museums so you know what you're aiming for.