Definitely not a quick fix!
Richard Rosen has written a sensible and practical book about a form of yoga that has often been misinterpreted and trivialised, particularly by the new-age press. If you're looking for something that will tell you simply to "breath-in-breath-out and think beautiful thoughts", this isn't for you.
An Iyengar trained teacher with over twenty years experience, Rosen explains pranayama in a way that western students can respond to. He describes (with plenty of excellent illustrations) the preliminaries, the practice, what you can expect and how it helps you, in a style that is chatty without ever being superficial or condescending. He estimates that if you work through this book conscientiously it will take you at least eighteen months to complete the programme.
If you're serious about exploring this fascinating form of yoga, and have no teacher near to you (and even if you have, it's still worth reading) this is the one to buy.