The problem is, leeneia, that recent times have seen an enormous change in theatre sound and lighting. Old lighting systems have been stripped out and replaced by LEDs and manual sound desks and their associated peripherals (reverb/delay units, compressors, feedback destroyers etc) have/are being replaced by digital.

You will see old lights for sale at excessive prices in antique and “vintage” shops along with second hand manual sound desks at bargain prices in what is left of our music shops. Analogue sound has some advantages over digital but the opposite is also true. The main advantage of digital over analogue is that it is far cheaper and you can do more with it.

Unfortunately, just like the old arguments between satelite tv systems or VHS v Betamax, there is, as yet, no common operational standard. They all do the same thing but in diffrent ways. Mainly for this reason, you won’t find a book which explains everything and, if you do, it will likely be somewhat out of date.