In the mid-2000ies, I installed a photo lab at my mother's house:
Développement des films: I developed black and white and color films. I used to make my own developers (the solution used to develop the film) from raw chemicals. I mostly used The Film Developing Cookbook by Anchell and Troop for that.
Formats: I mostly used the standard 135 format but I also made photographs with medium and large format cameras.
Studio: I also had a small studio in the basement of my mother's house.
The books I liked the most: