Introduction to Praxeology & Economics | Where to start?

Praxeology is the study of Human Action.  The best developed subdivision of Praxeology is Economics (Austrian Economics) which is best characterized as peaceful cooperation / voluntary exchange between active members in society.   

People that advocate this position, believe that empirical methods are not suited to obtain new knowledge with regard to economics and human action. This is because there are no constant relationships in Human Action.  Unlike physics, where there are constant relationships such as Gravity = 9.81 m/s^2 or mass of an electron = 9.10938291 × 10^-31 kilograms.  In physics empirical method is the only way to obtain new knowledge as these constant relationships were previous unknown and through hypothesis and experimentation one can discovery these laws. Therefore, Praxeology is a priori.
Most specifically synthetic a priori (See Immanuel Kant video)
Therefore, starting at “The Action Axiom”, all of economics as well as other areas of Human Action are deduced step by step (via deductive reasoning).  To get an understanding of how this works as well as the implications of the Action Axiom, the starting point is “Man, Economy, and State” – By Murray N. Rothbard <- free PDF of entire book.  Since this book is 1500 pages, I suggestion just reading Chapter 1.  In the above PDF that starts at page 66, and it is about 50-60 pages.  It will be a journey worth exploring.
A more specific and advanced topic discussed in Man, Economy, and State, is the concept of Money.  It is introduced into the above book on page 755, and to fully understand how it fits into the system 9 chapters of reading are required.  However, an amazing book, that is written by the same guy provides an overview and the main points of this discussion.  It is fascinating for its historical discussion and implications to our future.  It was written more than 30 years ago and it is more applicable now than ever (since governments around the world are expanding the money supply via Quantitative Easing, etc).  It is an easy and engaging read.  What has the government done to our money? <- free PDF of entire book.  It is less than 100 pages, but will really give you perspective of what money actually is, the history of how it came into being and the problems with attempting to manipulate money.
FEW ECONOMIC SUBJECTS ARE more tangled, more confused than money. Wrangles abound over “tight money” vs. “easy money,” over the roles of the Federal Reserve System and the Treasury, over various versions of the gold standard, etc. Should the government pump money into the economy or siphon it out? Which branch of the government? Should it encourage credit or restrain it? Should it return to the gold standard? If so, at what rate? These and countless other questions multiply, seemingly without end.
First Paragraph of Chapter 1: What has the government done to our money?
Lastly, I will end off with the final paragraph from a much older book, but was the foundation of praxeology.  Mises was the central figure in the modern development of it (1930’s), his book was named Human Action <- Free full PDF.  It is a treatise as well standing at 1000+ pages but it is much harder to understand compared to the more modern Man, Economy, and State, since the new book is a step by step explanation of all things related to economics. The final paragraph of Human Action demonstrates the importance of the understanding of Praxeology.

XXXIX. ECONOMICS AND THE ESSENTIAL PROBLEMS OF HUMAN EXISTENCE

3. Economic Cognition and Human Action

Man’s freedom to choose and to act is restricted in a threefold way. There are first the physical laws to whose unfeeling absoluteness man must adjust his conduct if he wants to live. There are second the individual’s innate constitutional characteristics and dispositions and the operation of environmental factors; we know that they influence both the choice of the ends and that of the means, although our cognizance of the mode of their operation is rather vague. There is finally the regularity of phenomena with regard to the interconnectedness of means and ends, viz., the praxeological law as distinct from the physical and from the physiological law.

The elucidation and the categorial and formal examination of this third class of laws of the universe is the subject matter of praxeology and its hitherto best-developed branch, economics. The body of economic knowledge is an essential element in the structure of human civilization; it is the foundation upon which modern industrialism and all the moral, intellectual, technological, and therapeutical achievements of the last centuries have been built. It rests with men whether they will make the proper use of the rich treasure with which this knowledge provides them or whether they will leave it unused. But if they fail to take the best advantage of it and disregard its teachings and warnings, they will not annul economics; they will stamp out society and the human race.

Lastly, Economics,  is value free.  Since it is the study of Ends and not Means (which is subjective choices of people), it is objective in the sense that it doesn’t make value judgement on how people should act, rather if they subjectively choose an End, the means to get to that end can be analyzed for its validity.  Since if it can be shown that by using a specific means will actually result in a different end than the one that is aimed at, a reasonable person must abandon that choice of means as it isn’t going to result in the End sought.