I have been practicing Kriya Yoga for several years. I first learned about it by reading Autobiography of a Yogi by Paramahansa Yogananda; one of the greatest and most valuable books I have ever read in this lifetime. Yogananda was an especially gifted writer and this book for the most part is very easy to understand if you're ripe for it.

I personally have found that this book not only opened me up to new spiritual methods and perceptions, but also made sense out of all the things I learned during my Christian upbringing. This book does a great job of showing that the real underlying deep essence of all religions are based in the practice of Yoga.

Kriya Yoga is a scientific technique that anyone from any faith can practice and it can bring you extreme calmness and union with the divine which is always all ways around you and inside you everywhere and nowhere. I highly encourage anyone who is seeking more understanding and clarity for their life to read this book.

There is a free copy of the book online that you can read at the following link: http://www.crystalclarity.com/yogananda/

I'd recommend reading the book in its physical form for intimacy's sake but this link is a good place to start.

After reading the book and you want to learn the techniques of Kriya Yoga, you will find that there are a few different organizations out there offering Kriya Yoga. My personal choice has been to join the lineage found at http://www.kriya.org

The book emphasizes the importance of having a guru-disciple relationship with a living master. Paramahansa Prajnanananda is the current head of the lineage, you can find out more about him and the other kriya masters described in the book at the website or if you have any questions please feel free to send me a message.

Another particularly awesome book that I recently read called "How to Know God: The Yoga Sutras of Patanjali" with commentary by Swami Prabhavananda and Christopher Isherwood is an excellent life manual for any and every human being. 

Read at your own pace and don't feel the need to rush into these teachings but if you are really thirsty for the experience of the soul within you then by all means drink from the fountain of knowledge and everlasting life that becomes apparent by reading and comprehending these priceless books.

Namaste