The following four first books are small (5 by 8 inches or 13 by 20cm). They are not thick, all between 160 and 190 pages and inexpensive ($10 or less!).
They can all be purchased through the internet.
The fith is a full size book, a little thicker and more expensive, but well worth to own.
All of them are easy to read, even though Einstein's book requires several readings.
The last book written by the author, has been inspired by all the other and many more. Yet "there is nothing like it"! A comment made by the technical editor of the book.
None of these books use mathematics they all are for laypersons.
Scientific books for non mathematical oriented minds
"Relativity, The Special and The General Theory". This book originally written in German (1920) by none else than Einstein himself is available in English in all book stores and on the internet. You can also consult it or read it in its entirity free of charge at: Relativity. The Special and the General Theory
"Introducing Quantum Theory", by J.P. McEvoy and Oscar Zarate. ISBN 1 84046 057 1. This book is a must! It is oustanding! If you do not understand what is going on, once through you will understand why you cannot understand!
"The Character of the Physical Law" by Richard Feynman. First MIT Press Paperback Edition, March 1967. Richard Feynman is a favorite physicist writer/popularizer of physics. This book is a must to feel the spirit that motivates professional scientists.
"The Periodic Kingdom" By P.W. Atkins. BasicBooks A Subsidiary of Perseus Books, LLC. This book has definitely be influencial in the choice of the words "Harmony of Reality", title of the book listed below. It shows how science can also be poesy.
"Great Physicists. The Life and Times of Leading Physicists from Galileo to Hawking" By William H. Cropper. OXFORD University Press 2001. The history of physics is not only wonderful to discover, this book makes also one get in the shoe of the physicists of today and yesterday.