This page has some recommended marine diesel books, and lists some hands-on training in marine diesel engines, as well as electrical systems, offered for recreational boaters in the greater Seattle area.
By Charlie Wing. Great for anyone, but especially beginners; you can’t hope to fix it if you don’t even know how it works. A great place to start. Available in book or electronic version.
Or "Marine Diesel Engines", or any other book or article by Nigel Calder. Available in book or electronic version.
By Peter Compton. A good reference. Available in book or electronic version.
Marine Diesel Engine classes are part of the Recreational Boater Continuing Education series at Seattle Maritime Academy.
Hands on seminars in Marine Diesel Engines and Marine Electrical systems at the NW Center of Excellence for Marine Manufacturing & Technology in Anacortes.