Csikszentmihaly, Mihalyi. Flow: the psychology of optimal experience. Harper Collins, 1991, ISBN 0060920432.
We want to be happy. But what is happiness?
Happiness has several components, but this author has brought out an important pattern that is involved in many of the answers.
Flow is that wonderful state into which we are sometimes lucky enough to be immersed---when we can focus sharply on a single activity that challenges us to integrate many of our faculties in a single pursuit, and block out all the daily noise.
It could be downhill skiing, or music, or programming, or carpentry. We might have hours of flow or six seconds that seem like hours.
Read this book for important yet accessible ways to improve the quality of your life. If you are in management, it can tell how to improve life for those in your authority.
A closely related factor is the physical environment of your pursuit. I am fortunate to have several activities that can get me into flow, e.g., music, writing (prose or programming), and data entry. See my review of Peopleware for specific information about promoting flow for software engineers.