The life and mission of Sister Faustina,the seer of the Sacred Heart of Jesus. Written by Maria Tarnawska(translated from Polish into English by Anne Hargest) UK imported edition with many black and white photos throughout.
You may care to read this before reading St. Faustina’s diary. This helped me understand what St. Faustina was going through when she was writing her diary. It deepened my devotion to the Divine Mercy of Jesus.