This is unquestionably the best book on the subject that I've read. It strikes the perfect balance between factual -- "Here is what is available, here is the law, here is the means by which you can download, here is how to minimize your legal risk" -- and philosophical -- "Here is a breakdown of music industry sales, here is Harlan Ellison's opinion on bookwarez, here's what crackers have to say about zero-day warez trading, here's the dumbass laws that have been proposed to allow rights-holders to remotely shut down your computer via secret kill-switches, isn't that crazy?"
Wang is an accomplished tech writer and a stand-up comic, so Steal This File Sharing Book is both funny and lucid. It assumes almost no technical knowledge and it walks the reader through everything from file-compression protocols to anonymizing proxies to the notorious cross-stitch-pattern-trading underground.
If you want to figure out how to file-share safely, avoid spyware, not get busted, and learn about the morality and ethics as presented by all sides of the file-sharing debate, this is the book for you.