According to the preface, what specific text is recommended for Sai devotees to study together, and why is it so important?

The preface strongly recommends the Shri Sai Satcharita for devotees of Sai Baba. As detailed in Chapter 0, this sweet, inspirational, and grace-filled biography was written by the late devotee Shri Govind Raghunath, also known as Annasaheb Dabholkar. It is considered one of only two such detailed, poetic, and comprehensive works in Maharashtra suitable for Parayans and Saptahs. By having his biography written, the Sadguru accepts service from the writer and the congregation of devotees who study it, making the collective reading of the Shri Sai Satcharita a powerful community practice.