No Excuses! The power of self-discipline by Brian Tracy is a wonderful guide on how to strengthen your self-discipline, and how it can benefit many aspects of your life, such as finances, career, health and relationships.

The original is over three hundred pages long, and the author uses verbosity to reinforce some of the principles. If you want practical advice without the tedium of subliminal reinforcement, these cliff notes neatly summarize the key points to get your life on track.