This is the first book that I have ever read about Plato. While it is not the best book in this series - it should have been longer - it is still a good read and worth the $... you'll spend for it.
The best thing about this book is that, rather than just focus on Plato's own philosophy, generous mention is also given to his place in culture and the history of the interpretation of his works. More than anything, this makes for a more enjoyable read, but it also gives us a clue as to how certain practices and ideas that are still current today have (at least some of) their roots in Plato.
However, when it comes to Plato's own thought about different things, this book is a bit lacking. His theory of the forms is given short mention, while an entire chapter is devoted to his views on sexuality. Given our current cultural milieu, such a focus on sexuality is indeed interesting, but was sex really so central to Plato's philosophy?
While it is important to note the differences between his own culture and ours, it is more important to note the main currents of his thought, especially given the constraints on length for this book (the subtitle is, after all, "A Very Short Introduction"). If she had explained his most important and most famous ideas more, such a focus would not seem so disproportionately out of place.
Yet, it is also worth noting that Annas' goal seems to be to write a book that is simply a good place to *start*. The book ends with an invitation to do philosophy rather than to simply know about it which is, so to speak, in the very spirit of Plato himself.