Philosophy is a vast subject and to write a small book encompassing a significant part of it seems to be an impossible task. It has been achieved in this work by writing twelve books, each of which is an introduction to one area of philosophy, and then taking the forewords from these and forming them into a single volume. It works pretty well - the books were originally written for teenagers, so the style is easy to read. Is death final? Is there a God. What do we mean by beauty and what part does Art play. If you want a book which discusses these big questions but doesn't become too taxing then this book fits the bill admirably.
As a scientific website, most of the philosophical books reviewed here are be related to the philosophy of science. This doesn't fall into that category - it's philosophising about how to live your life, rather than philosophising about the nature of the universe. Hence theres nothing about quantum wierdness, and very little about ideas of consciousness. There is a chapter on time, but it doesn't go very far into the usual questions of the arrow of time and suchlike. Indeed one could say that the book is more of a collection of the authors ideas than an introduction to the subject of philosophy. But there are plenty of suggestions for further reading for each subject area, so on balance I would see this book as a good starting point for the study of the subject.