>>2560917>>2561230First and most inconsequential: General Survival guide.
Ask other anon's about their preferences and go-to's, this is just the one I bought myself.
It contains a brief glance at survival skills you might rely on in a short term survival situation, some of which will be important to your day-to-day camping and hiking. Knots are good example, which this book does have a few of, and is much more intuitive to use over searching it on your phone at a whim.