Fox,
Welcome to the club.
When I looked up the towing capacity of my F-150 with a WD hitch I thought; “wow 9000 lbs. plus” I will never need that much weight.:W
But, thanks to the members of this board I learned that the little sticker in the door jamb gave me the max cargo weight (for my specific vehicle) which includes the tongue weight. And, as they say “There’s the rub”; with my TV loaded the added tongue weight brings me very close to the max cargo limit.:S
You may not find the book you are looking for but do not be afraid of asking questions on the forum. The only dumb question is the one that is not asked.