If you have boys...

If you have boys between 8 and 80 this cool book is for you. The Dangerous Book for Boys by Conn and Hal Iggulden.

From the publisher:

The bestselling book for every boy from eight to eighty, covering essential boyhood skills such as building tree houses, learning how to fish, finding true north, and even answering the age old question of what the big deal with girls is.

In this digital age there is still a place for knots, skimming stones and stories of incredible courage. This book recaptures Sunday afternoons, stimulates curiosity, and makes for great father-son activities. The brothers Conn and Hal have put together a wonderful collection of all things that make being young or young at heart fun---building go-carts and electromagnets, identifying insects and spiders, and flying the world's best paper airplanes.The completely revised American Edition includes: The Greatest Paper Aiplane in the WorldThe Seven Wonders of the Ancient WorldThe Five Knots Every Boy Should KnowStickballSlingshotsFossilsBuilding a TreehouseMaking a Bow and ArrowFishing (revised with US Fish)Timers and TripwiresBaseball's "Most Valuable Players"Famous Battles-Including Lexington and Concord, The Alamo, and Gettysburg Spies-Codes and CiphersMaking a Go-CartNavajo Code Talkers' DictionaryGirlsCloud FormationsThe States of the U.S. Mountains of the U.S.NavigationThe Declaration of Independence Skimming StonesMaking a PeriscopeThe Ten CommandmentsCommon US TreesTimeline of American History