Hints to game features in written books in chests to help new players.

I've always imagined these books to be written adventure stories of past players. So not just outright telling the player, but making it so the player can read the story and discover for themselves by trying to recreate what the adventurer in the story did.

For example: the Wither. Out of the box, no new player has any way to know the Wither exists or can be summoned, so a story to hint at how to make it and that it exists could be useful.

Another example is the beacon. While there is a recipe for the beacon top itself, there's no direction in the game on building the base of the beacon.

Things like this can help remove reliance on google and youtube.