Are there any specific books mentioned that are ideal for group study or 'Parayans' to build a community of Sai devotees?

Yes, the source material explicitly identifies a key work for building community through collective study. Chapter 0 explains that for a focused Parayan on Sai Baba, the 'Shri Sai Satcharita' written by the devotee Shri Govind Raghunath alias Annasaheb Dabholkar is the most suitable text. It is described as a recent, sweet, inspirational, and grace-filled biography of Shri Sachidanand Samarth Sadguru Sai Baba Maharaj. The text emphasizes its unique status as a detailed work, making it perfect for Parayans and Saptahs that bring devotees together in shared worship and study.