The Penguin Guide to Vaastu is a meticulously researched book that seeks to place the ancient Indian art of Vaastu in its proper perspective as a highly evolved science. Supplemented with beautiful illustrations, this authoritative volume combines ancient wisdom with the needs of a modern and transitional society.
The book is a decent introduction to Vaastu. It is completely valid in that the author stresses the importance of integration of sister fields of Jyotisha, Yoga, Ayurveda, Mathematics, etc along with Vaastu. For me personally, this adds a new depth to my current understanding/admiration of the architecture, be it the Ajanta/Ellora Caves, Forts of Rajasthan, Golconda, Konark Sun temple, Brihadeeswara temple, etc.
A one time read. Pick it, if you are utterly new to Vaastu.