in non-fiction, Patent It Yourself by David Pressman influenced me quite a bit, along with large sections of the patent examiner's manual. Even without having any particular purpose, the body of legal thought in regard to creativity is deep and fascinating. You can begin to feel instinctively that certain sorts of rulings and cases must exist, and then find them, because the key concepts and purposes predict them. The challenge of respecting and balancing the interests of different parties, of distiguishing mere ideas from full-blooded achievements, has great drama in it too. And it's poignant and hilarious what crazy things people have painstakingly developed, that one has never heard of.