Not everyone but since this is HN I'll say Developing Quality Technical Information: A Handbook for Writers and Editors. It's intended for technical writers as

Not everyone but since this is HN I'll say Developing Quality Technical Information: A Handbook for Writers and Editors. It's intended for technical writers as an audience, and there's a couple chapters developers can skip that are about formatting with pretty diagrams and using DITA and stuff, but at least 80% of it is applicable to all kinds of writing that devs will have to do, and everyone needs to be able to communicate with the written word effectively. Literally every developer should read this book (and everyone should read some writing book relevant to their own field). It's amazing.