First, I'll tell you about the good one: "How to Think Like Sherlock: Improve Your Powers of Logic, Memory, and Deduction", by psychologist Daniel Smith. Essentially, Smith derives examples from the canon of Sherlock Holmes lore, and compares them to modern-day examples and tips, to teach you how to think more logically and laterally, how to improve your memory, and how to solve crimes. There are sections on how to look for clues, how to read clues, how to disguise yourself when going undercover, etc. This is a very good book.
The second is a so-so book, from Scott Beatty, called, "The Batman Handbook". There are a few issues with authenticity, as regards his research - particularly in the combat section, - but from my own investigation, the rest of the book seems relatively solid. He has done his homework, but in more than one case, he just looked for some of the most famous names in a field of study, and took their word for things. Personally, I'd say, take the combat section with a grain of salt; the rest is pretty solid, and though the book is a piece of fiction, it's a fairly well-researched piece of fiction.
If you can get your hands on these books, they're great introductions to fighting crime and saving lives. Naturally, you want to go further than what these two books, alone, can provide, but they're a decent foundation; easy to understand, and great to transition from, into more complex, detailed instructionals.