Jack Kornfield is a highly regarded teacher in the Theravada Buddhist tradition, and his teaching, books, and recordings have been instrumental in bringing that tradition to the West. I don't think this book is structured very well, but it's worthwhile. There's interesting introductory material and a great overview at the end, both of which are terrific for a reader who is just starting to learn about vipassana (insight) meditation and the Buddhist tradition, but in the middle there are some very long sections that are really only useful to someone who is already some distance down the path.

I don't know if this is Kornfield's best book to introduce these topics, but I haven't found anything to suggest that his other books are a better place to start.