I would like to recommend two books by Dr Albert Ellis ( considered the grandfather of CBT on which this program is based ) One is the New Guide To Rational Living and the second is Rational Emotive Behavior Therapy - It Works For Me - It Can Work For You Too
The second book is autobiographical and Dr Ellis was quite a controversial as well as influential figure in psychotherapy so he uses quite colorful language and gets away from the scientific jargon of most psychotherapy books.