M. J. V. Fennell - Overcoming low Self-Esteem - This book teaches you to apply Cognitive Behavioral Therapy on yourself while emphasizes on low-self esteem. I'm in the very beginning of it, but so far it describes the different sides of the problem extremely well. If he want to get deeper, Rollo May's Man's Search For Himself is very good book, as well as Emerson's Self-Reliance.