A very long time ago, somewhere around 1993, I wrote several manuals to help people understand how to use two of the most mis-understood aspects of photography; The Zone System and Color Printing. I present them here for your edification.
Though written over a decade ago, neither manual needs extensive updating. In the Color manual, the chemicals used for processing may have changed names. Some of the companies may have changed and some of the referenced books may be out of print. Otherwise, the concepts remain unchanged.
I hope that you find them useful and worthwhile.