Find a library, or get a copy of "Chapman's" [Chapman Piloting & Seamanship] and you'll get a lot of useful information fast, especially the names of things on and off the boat, and proper procedures. One of the many books
on knots will also let you surprise him.
and systems gets a bit more complex, and sailing itself is best learned "hands on" rather than through the confusion of new words in books
. "Colregs", the Collision Regulations
, which also include right of way rules, lights and shapes, is available directly online and if you learn that stuff--guaranteed he'll be surprised and pleased. If he races, there are racing
rules also available online, and again, he'd be floored if you knew them.