There is a lot of knowledge already known out in the world and through history. There is great wisdom available, you just have to look for it. Mostly you will have to find translated versions if you don't read in the original language and who translates sometimes is very important. Just translating is one thing, understanding a language in the period in which it was written is important as well as an understanding of accurate history during that period.
That being said, it's all in what you are looking to find and what you find, which may not be what is there, or may be an epiphany that others who read the same words, do not "see". One of my favorite sayings is, "Even the village idiot has his story." It means that you can find wisdom anywhere, if you pay attention. Staring at a blank wall can give you great insight, if you are prepared to "hear" it.
I've been told that knowledge with experience, is wisdom. Acquiring information, as in book learning, simply isn't enough. Experience, isn't enough either, but extremely valuable. Still, in adding to experience, book learning, you can go leaps beyond by utilizing other's experience, who have mostly likely tried the wrong ways. That being said, sometimes revisiting those wrong ways can lead you in the right direction because those others missed something. But you don't want to haphazardly just waste your time on that, either.
Wisdom is a tricky things sometimes.
When I was starting high school I asked a lot of questions. Until one day a teacher, frustrated with my constant questions finally told me I was holding back the class from moving forward and I could question him after class. He said I was asking good and relevant questions but I should give others a chance to ask them. Except that I wasn't seeing that anyone else was asking these questions. Still, I got his point.
He also said, if I would just wait and listen, to pay attention closely, I would most likely hear the answer at some point in the class, or someone else would as the question. Or, I would simply find the answer within myself before the end of the class period. He told me that I may already know they answer (to paraphrase him) if I just listened to my own interior dialog.
That may have been the greatest single piece of advice I had ever been given.
People suggest reading Art of War for business awareness and I fully agree. It gives you a template you can hone to your understanding of a compassionate way, but you do have to read it first.
Another book that I found perhaps more useful is The Prince by Niccolò Machiavelli Written c. 1505, published 1515, in business endeavors. Many read his book as a very dark book but I found it useful in warning me, making me aware of things, more than how I should act toward others, and if you read it for that you are ahead of the game for those reading it to find how to abuse people in order to maintain power and rise above them.
There is another book I like on this type of book, a few really and there's others, but to be brief here's a few I'm fond of:
The Art of Worldly Wisdom by Balthasar Gracian
In a different vein and perhaps a bit more obscure but still useful, a few others....
The Art of Peace by O'Sensei Morihei Ueshiba
The Book of Five Rings (Go Rin No Sho) by Miyamoto Musashi
And the more esoteric....
Zen Essence The Science of Freedom Translated by Thomas Cleary
[Another is Rational Zen The Mind of Dogen Zenji by the same]
I Ching The Book of Change Translated by Thomas Cleary