This is a collection of essays, ranging from fairly topical (in the 30's) and technical to philisophical. It is the latter kind which are of more interest to the layman (like myself) and fortunately these make up the majority in this volume.
One of the most fascinating essays is the first, entitled "Individualism: True and False" in which Hayek clarifies what it means, dispelling many of the myths that are usually associated with it. It is not about greed and selfishness, nor is it about a rejection of society and a celebration of the individual. Nor is it a rejection of planning, a blind faith in chaos and freedom.
Another theme common to several of the essays in this book is the concept of knowledge in society and the problem for any centralised system of planning being that of how it gathers and processes the knowledge which is naturally localised and dispersed.
There is much more besides, and I cannot recommend this book more highly.