Here are some books that have shaped by business/technology skills over the years. Many of them, like Drucker, Mackay, Toffler, and Covey were recommended from my father. The one Drucker book I have is actually an original from 40 years ago. Over the years I know there have been many more books than this, but I tend to give them away. I also had a huge collection of programming and database books that I got rid of a while ago.