Welcome aboard. You are in great cruising waters, in a boat well suited to them.
In learning about diesel engines, and trawlers, I would recommend having a couple of books by Nigel Calder, Boatowners Mechanical and Electrical Handbook and his Marine Diesel Engines.
Even if you don't do all of your own work, ( I don't. Some places I just don't fit ), sit with the mechanic and learn what he is doing and why.
Have fun, and post pictures.
Cheoy Lee 40 LRC