The preface mentions two key biographical works. Could you tell me about them?

Certainly. Chapter 0 highlights two exemplary Guru biographies from Maharashtra that are considered ideal for Parayans. The first is the ancient and revered Guru Charitra, a sweet and graceful work by Shri Saraswati Gangadhar about Shri Samarth Sadguru Narsimha Saraswati Maharaj. The second is the more recent Shri Sai Satcharita, described as an inspirational and grace-filled biography of Shri Sai Baba Maharaj. This latter work was written by the devotee Annasaheb Dabholkar and is the specific subject of the preface.