I highly recommend Will Durant's revolutionary work on philosophy, The Story of Philosophy: The Lives and Opinions of the World's Greatest Philosophers. I call it revolutionary because, for the first time in about 200 years, it presented philosophy to the common man. It made philosophy understandable and made it seem practical and applicable to everyday life.
In the introduction to the book he explains what philosophy is and splits it into five parts. They are logic, aesthetics, ethics, politics and metaphysics. He defines logic as ways of thinking, problem solving and reaching conclusions. Aesthetics is the subject of beauty, ideal form and art. Ethics is about ideals of behavior. Politics is the subject of social organization - not just how to get elected :). Metaphysics deals with the underlying concepts behind the nature of existence, reality and being and the interaction of mind and reality via perceptions.
When I first read this I realized that Scientology not only covers all those things but it contains actual workable methods of applying the theory and principles of its philosophy in everyday life. For example the subject of logic is covered in "The Logics" which can be found in Scientology 0 to 8: The Book of Basics. How to easily and successfully apply this is covered in the investigations chapter of The Scientology Handbook. I personally have used these methods to solve many problems in my own life and in the lives of family and friends.
One particularly successful application was to a friend who had ended a disastrous marriage about a year earlier and was having a terrible time establishing a new relationship. Using the procedure given in the handbook we found the underlying reason for his difficulty and came up with a solution. A week later he started dating a woman whom he would never have considered asking out in the past because of the fixed ideas he had had before we applied Scientology logic to his situation. A couple of years later I found myself being asked to be the best-man at their wedding and now, 7-years later, they are still very happily married.