Economics in One Lesson by H Hazlitt and Jeff Riggenbach
Economics in One Lesson: The Shortest and Surest Way to Understand Basic Economics
This is the audio version for listening on your ipod or in the car. If you find it hard to find the time to read then audio books are great, it makes time in the car so much more productive and enjoyable.
If not the best one volume introduction to economics it certainly is the most enduring. Not just for Mums and Dads. Get your teenagers to listen to this as well. It is well written with everyday examples making it easy to understand. This book is not written like a textbook, ( thank goodness for that!).
You will find some discussion of the book on Mises (they are reprinting the book). You can read the whole book online. You can hear a sample to see if you are happy with the reader here