The E-Myth by Michael Gerber
Michael E. Gerber wrote this small business classic in the mid 90's, and popularized the idea of systematizing one's enterprise. The trick lies not in working as hard as possible to make widgets 15 hours a day, according to Gerber, but instead the goal should be to hire and facilitate someone else's ability to make those amazing widgets. Doing that allows the owner to strategize from the business level instead of being immediately buried under a mountain of WORK.