I found this book to be one of the most helpful and useful I have read for some time. It is mostly about your inner world, how you interpret life, how you react to events. It will not appeal to everyone because it is from the perspective of Eastern philosophy (ie India / China) rather than Middle-East religions.
It is not dogmatic, nor does it cut into traditional religions, rather it supplements them. Many of the ideas are from the 20th century---the important thing is whether they can help the reader or not.
I think most people will find a lot in here that will help them to interpret the world they live in. It is quite a short book, about 40 pages. You can also get a free ezine for further reading. It is in pdf. FREE
THE TAO TE CHING This ancient Chinese classic has almost hidden meanings that require your own interpretation. You need to think "outside of the square."
LIGHT ON THE PATH, Mable Collins. This short book, first published in 1888, is one of the fundamental books of the Theosophical Society, and of some Western Yoga schools. For many this is one of the most important books, which can be read over and over as your path circles the mountain. Each time you read it you will find new understanding. At the moment I am creating it as an e-book, that will be easy to read.
So watch this space!
LEAVES OF GRASS by Walt Whitman
Many people fail to see the significant spiritual nature of this book.
First published in 1855, revised and added to a number of times, this book of poems was vilified at the time, described as "indecent", largely because Whitman wrote about some subjects that were taboo. One critic, hmmm his name has disappeared now, wanted to "horsewhip" Whitman for writing something as disgusting as this. These days it is regarded as an American Classic, unfortunately at the time Whitman lived in poverty and had to self-publish.