i'd like to know the materials needed to successfully replace a gypsum ceiling board
This guy has a great tutorial and video on his blog. https://www.hometalk.com/2371202/why-i-learned-how-to-patch-drywall-and-you-should-too
Here are some helpful hints
A board? That sounds like you have a panelized ceiling?
Drywall commonly comes in 4x8’ sheets in the US, with thicknesses ranging from 1/4-5/8” and 1/2” being the most common. It also can be purchased in 4x10 sheets.
For a ceiling, you’ll want Lightweight drywall, and I know Home Depot carries it for a bit over $7.
I swear by fiberglass drywall tape, drywall screws and use 3 blades: 3”, 6” & 10”. Paper tape is preferred by some in the corners because it holds the crease better.
Go easy on the “mud”, sanding is a pain in the neck, literally.