Steal this book, by Abbie Hoffman [0]. Certainly not unknown, but not exactly something you find by accident. It's a book detailing 60s counterculture activities, and took a lot of work to find a publisher. Really interesting look back on history at general creative problem solving, and very entertaining. The most common theme in the book is "how to do x, for free".

[0] https://en.wikipedia.org/wiki/Steal_This_Book