The game already includes various recipe books but sometimes one might have problems locating the sources of ingredients. This is where these books would come in. For example, they would explain that cattails grow only in swamps and that they could be used to produce plant fiber, which in turn could be used in various crafting projects. The text would then point to specific further literature, the actual book names that already exist in the game, which would contain some or all plant fiber related crafting recipes.
Or perhaps have a paper that would hint about ways to acquire acid; specifically you would have to find a car battery and disassemble it while having a sufficient amount of empty containers in your inventory; 500ml for the acid and 2000ml for the water. (not probably accurate numbers, but anyway). Also mention that a skilled chemist would be able to refine water into acid.
Some type of electronics magazine might explain that heating elements are often found in kitchen ovens and laundry machines, and in most devices that produce heat via electricity, such as coffee makers and hotplates.
A book titled “Swamps explained” might tell everything there is to know about swamps: the flora and the fauna, their harvest and uses; mention that swamps are a source of both fresh water and salt water.
A “leaked document” might give hints about how to manufacture “X”, where x is any commercial or protected product, and how the exact methods will be published in a book named “Y”, where Y is the in-game name of the book.
A creatively named “agricultural research paper” or a “food industry document” could list all sources of sugar.
A “medical research paper” could describe the effects of various drugs, such as Adderall, cocaine or cannabis; their strengths and their durations.
A car magazine might explain the three less-known statistics of a vehicle: the K aerodynamics, the K friction, and the K mass, and how to manipulate them to your advantage.
I guess I’m hoping to bring a bunch of the wiki into the game, so that new players would feel a little less lost in the game, and to enable as much gameplay as possible without actually having to resort to wiki.