Just because it isn't made up, doesn't mean it can't be hard to believe. Nonfiction books span the gamut of human experience, and some people have done unbelievable things. Nonfiction isn't limited to memoirs and biographies, either; it covers anything that isn't made up.
Take a Step Into the PastJan 07, 2013 Gary Martin's two volumes of The Art of Comic-Book Inking have become the industry-standard manuals for aspiring inkers seeking to take their work to the next level or for working professionals looking to broaden their skills base. Most of the D&D manuals, source books, adventures, novels and magazines of the 80s and early 90s featured the works of one of these five artists on their covers. Each edition of D&D had a different type of art that was unique to that version of the game. Art of the original D&D consisted of a lot of line drawings. Of this book is to teach pencil sketching, I believe that a new book, with all new writings and illustrations, will serve the purpose well. Sketching with color pencil is intentionally left out because I feel strongly that the basics in learning how to sketch and draw must start with a simple black and white medium. Pencil is very special.
History has always been a popular form of nonfiction, largely because there are so many different kinds of history. You can study everything from military history, to the history of quilting on the Canadian prairies. Anything people have ever done has a history, and in most cases you can find a nonfiction book about it. History covers everything from the broad sweep of empires to the personal stories of a single week in an individual's life. It's the story of humanity.

Even as the world grows more and more materialistic, people find themselves turning toward nonfiction books on religion and spirituality. These books provide many people a way to find meaning in a world that is moving faster and faster every day. You can find everything from closely reasoned apologetics for the major faiths, to New Age life guides in the same place. Perhaps you'll succeed at your quest for meaning between the pages of a nonfiction book.
Everyone Has to EatAll cultures have one thing in common; recipes. No matter what the culture, someone has written a cookbook, spreading cuisine around the world. You can find books on French, German, Italian, Caribbean, and just about any other form of cuisine you can imagine. In addition to cookbooks, there is also a whole world of diet books. Whether you want to lose weight, gain weight, or manage a health condition, there is a diet book to fit your needs.
Art and photography books bring the vision of the world to your very eyes. Art is fundamental to the human experience, and just one art book can show you millions of dollars' worth of old masters from around the world without the need to leave your couch. Photography books let you see the world as people like Ansel Adams and F-Stop Fitzgerald see it.
Just an interesting aside: this book was recommended to me by none other than Mike Royer (one of Jack Kirby's main inker), after I sent him an e-mail suggesting that he write a book on inking.