Ray's Plundergrounds are great, and there's a large selection of them on itch.io.

This is a useful technique for building out dungeons in Dungeon World. The pacing and variety of it is fun for the players. Johnn's newsletter is also worth signing up for.

I love lists of silly things like these. Highlights from this list include the Belt of Posture, Random Hat, Beef Knife, and Poorly Dancing Sword.

Jeremy's rewrite of Parley is one of my favorite changes in Homebrew World.

Some of them are Dungeons and Dragons specific, with references to short rests and whatnot, but many are just flavor.

Most of the answers are articles and not books, but there's a smorgasbord of high quality articles for Dungeon World GMs. One of them was already in this newsletter, the 5 Room Dungeons.

Dungeons can be a series of independent rooms, but this article describes how you can use clues to make the entire dungeon feel more connected.

This map creation software allows you to create fully 3D maps. There are both free and paid versions.