Do you mean a book or site for repairing folders? If so, I don't know of a general guide. There are a variety of sources scattered all around. For example, a Compur manual is available. People have put up a pages showing their stripdowns of a variety of shutters. Bellows repair methods are scattered around. Alignment, etc.
Much of the time it's a matter of extrapolating. Shutters are very similar once you learn one or two. Alignment is a matter of studying the specific model in front of you. The nice thing about folders is that they are usually distinct systems assembled into one unit, not fully integrated. So a shutter is a shutter is a shutter, no need to worry about how it interacts with the wind mechanism.