Swami Paramananda 
The Upanishads [EPUB ebook] 

The Upanishads are a collection of texts that contain some of the central philosophical concepts of Hinduism. They are based on principles like samsara, brahman, atman, karma, dharma and moksha and form the core of Indian philosophy. This version is an English translation by Swami Paramananda as part of his mission to spread the eastern teachings of Hinduism to the Western world. Easy to understand and simply written, the thought behind this text is to know your SELF and follow the wisdom within the text to lead a wholesome and spiritually centered life.
Swami Paramananda was one of the early Indian teachers who went to the United States to spread the Vedanta philosophy and religion there. He was a mystic, a poet and an innovator in spiritual community living.