Short answers, pulled from the story.
The Book of the Dead began developing in Thebes around 1700 BC. Initial ownership restricted copies to royal family members only before democratization expanded access over time.
Anubis led the deceased into the presence of Osiris for judgment where a pair of scales weighed the heart against Maat's ostrich feather representing truth. If the scales balanced, the deceased became maa-kheru meaning vindicated or true of voice while Ammit the Devourer waited to eat hearts that failed the test.
One scroll cost one deben of silver roughly half a laborer's annual pay. Papyrus itself proved expensive leading to reuse creating palimpsests in some cases.
Karl Richard Lepsius published a translation in 1842 introducing the name Book of the Dead. He coined das Todtenbuch translating it into English for modern audiences.
The last use of the Book of the Dead occurred in the 1st century BC. Hieratic script became common from the 21st Dynasty onward replacing hieroglyphs entirely.