Dear Shammi,
Excellent book.. without doubt..
I have read this before and its one of my prized collection amongst others published by Divine Life Society (DLS) which Swamiji started on his return from Malaya. The society believes in dissemination of knowledge and Indian philosophy.SERVE LOVE MEDIATE REALISE is a simple example of motto of the *DLS.
Its worth mentioning here that HH Swami Shivanandaji himself a medical doctor enlightens us with his simple yet powerful messages in form of various books so are other books by various saints incl. HH Swami Chidanandaji & Swami Krishnanandaji.
I would recommend everyone interested in such books to visit
The Divine Life Society site for numerous books which are available for free download.
Haresh