Leo,
There are
manuals for OpenCPN on the OpenCPN.org website:
https://opencpn.org/OpenCPN/info/manuals.html
The User Manual is there. A User Manual is included in the OpenCPN program. The manual in the program is opened under the question mark below the top left (three-bar menu icon) which opens the "About OpenCPN" dialog box. "Help" at the bottom of the box opens the User Manual.
Rick Gleason is the best person to contact concerning development of a classroom in a book. Send a Private Message to rgleason in this forum.
Paul