E-Myth
E-Myth, written by Michael Gerber, discusses why most small businesses fail. While it's not a real estate focused book, it explains why most real estate investors fail. There are three parts to the successful small business person: the technician, the manager, and the entrepreneurs. Most of the people who get into their own business are the 'technicians' who do all the day to day work. However, they don't create a vision or plan, nor do they create systems or processes. And when things hit the fan, they end of quitting. A real eye opener and explained very well.