There are several books about Kriya Yoga.
The main book is "Kriya Yoga" written by Paramahamsa Hariharananda.
Kriya Yoga - 6th edition
No equivalent book on Kriya Yoga has yet been written. It is an in-depth study and exposition of the authentic Kriya Yoga by a master who had in his lifetime practiced it, mastered all of its highest techniques, and achieved the highest spirituality of nirvikalpa samadhi -- the pulseless and breathless state. He learned Kriya Yoga from the great masters and authorities like Swami Shriyukteshwar, Bhupendranath Sanyal, Paramahamsa Yogananda, and Swami Satyananda.
Paramahamsa Hariharananda's discourse regarding the scientifically proven benefits of Kriya Yoga makes this book a rare treasure for any sincere seeker. The world-renowned master describes the stages of spiritual transformation in detail, including many experiences that sadhaks, even those in family life, may encounter while practicing. At the same time he uses his unique scientific approach to explain how physical and mental functions also improve. Revised and Augmented 6th Edition.