This might be Mises's best-selling book. It is a very clear explanation of the basics of economic policy: private property, free trade, exchange, prices, interest, money and inflation, socialism, fascism, investment, and much more. As Mises discusses each topic, he addresses the many merits of market institutions and the dangers of intervention.
These chapters were originally delivered as lectures in Argentina in 1959, at the University of Buenos Aires, and later written up in prose. Mises had urged Argentina to turn from dictatorship and socialism toward full liberty, so there is a special urgency behind the cool logic employed here. The book's continued popularity is due to its clarity of exposition on the ways in which economic policy affects everyone.
It is a very good text for undergraduates studying economic policy, and for anyone who wants to gain a fundamental understanding of the interaction between market forces and government intervention.