Ray Monk is the author of the exceptional biography of Wittgenstein, DUTY OF GENIUS. So, who better to write a book about how to read W? And I admit the minute I saw Monk's name on the book I picked it up. But I am a little disappointed. The idea of this series of books is to select excerpts from the works of an author and then look at each selection in detail as a guide to reading the author's works. I fear that it doesn't work here, though. I suspect that someone who was not already familiar with W would find this less than helpful. Monk's selections from W are interesting, and not the obvious ones you might expect. But I did not come away with any new epiphanies concerning W, which is what I hoped for. (Other than the fact that I should look at his Last Writings On Psychology.)
You might be better off just reading something W wrote instead; I would recommend ON CERTAINTY.

There is universal consensus that Ludwig Wittgenstein is one of the greatest and most original philosophers in the last century. However, agreement as to a correct interpretation of the philosopher's work, particularly Tractatus Logico-Philosophicus and Philosophical Investigations, really depends on who you read; in fact there seems to be universal disagreement as to the "correct" reading of his work. That's why Ray Monk, the author of this text and the best selling biography of Wittgenstein, "A Duty of Genius", offers an apology in the Introduction, he writes,

"It is extremely presumptuous to publish a book called How to Read Wittgenstein. I apologize in advance for doing so and want to make clear that what I offer here is only _one possible_ way of Reading Wittgenstein." (P.1)

As Wittgenstein's biographer and a professor of philosophy, Monk is more than qualified to write this book, and the interpretations he proposes are clear and illuminating.

The text begins with a short biographical sketch of Wittgenstein, then tackles the most widely interpreted and difficult philosophical texts of the twentieth century, the Tractatus Logico-Philosophicus. Monk must be an excellent teacher because he throws light on the work, indeed clearing up a few of my own misunderstandings of the Tractatus. He explains Wittgenstein's early work and his transition period, around 1029-30, where his views on philosophy changed considerably, known as Wittgenstein's later period.

Close to the end of Wittgenstein's life, his philosophy began to branch out in new directions. In the work, Last Writings on the Philosophy of Psychology, he discusses the notion of Imponderable Evidence. This is particularly fascinating, as he proposes evidence that can be seen as evidence for a particular judgement but cannot be described. As Monk explains, this work was an attempt to distance him from those who look to science to provide psychological insight, and "...those in the humanities who have become convinced that understanding another person, having access to their inner life, is possible." (P.104)

I believe Ray Monk has touched the core of Wittgenstein's philosophy, explaining many of the philosopher's difficult concepts in a very clear and highly accessible manner. This would be an advisable text for any undergraduate embarking on a Bachelors degree in philosophy.