Unfortunately, there isn’t a single book that covers all aspects of the Turbo Diesel version so we ended up getting two. You should be able to work most stuff out between those.
Haynes manuals are great but they never covered Diesel Transporters. It’s still worth getting it for the other bits (suspension, transmission, body etc) but ignore the engines and most of electrics as they are completely different.
JK published the missing Diesel manual and for under a tenner you get docs for 1.6, 1.6TD and the rare 1.7 diesel engines as well as some info on clutch, transmission, steering, suspension and so on. It includes a handy electrical wiring diagram (although it would be better printed in color).
There are also some decent online resources listed on our links page.