A belter of a book. Assuming you are reasonably OK at woodwork, and know one end of a guitar from another - otherwise you wouldn't be considering a project like this in the first place, Melvyn does not waste time explaining which end of a chisel is the dangerous end, or spend 50 plus pages showing examples of his work. He demonstrates a few styles of guitar - eg a bolt on neck, a through neck, a carved top etc, you could copy one exactly, or (more fun) design your own around his principles.
He explains a bit, but not too much, of where the electric guitar came from, and the early pioneers of the instrument, and also the effect on playing, of using different types of wood, fingerboard radius etc....all helping you come up with your design. Technical stuff like fret spacings is explained, and again copy one of his scale lengths, or go for your own. Electronic stuff is covered - basic, but ideal for the non-electronics person - as an example - if you could figure out the working of a bicycle lamp, you should be OK with his schematics. In short, everything you need to know is covered in sufficient detail to allow you to build a guitar, without going too deep into any one area. If you wish to build something so radical it takes the guitar industry by storm, you may need to find a more specialist book as well, to cover that area. The only down side is there are no drawings of plans for guitars for those who simply wish to copy an existing design. Don't know how important that is though! There is also a handy contacts page to get the gear from.