Oh, I remember trying to learn all the vocabulary when my kids got into showing poultry.....They had to know all sorts of stuff about birds if they wanted to have a fighting chance at placing in poultry showmanship, so I sort of picked it up by contamination.
So, just some quick terms to help a bit before your broodies and the vocabulary and chicken math make you pull your hair out (lol)....
Hackles are the feathers on the neck. Saddles are the feathers on the back of the roosters (think of a saddle on a horse and that will help you remember). Sickles are the usually long and arching feathers over the tail of the rooster (absent, though, in hen feathered breeds like the Sebright)....
Ducks have a whole set of vocabulary words all their own, BTW, just to keep things confusing....
Good luck with your broodies! IME, it's catching--once one starts the others seem to follow....
Catherine