How can a devotee render service to their Sadguru through books?

According to the preface in Chapter 0, a Sadguru accepts service from devotees through books in two primary ways. The first method is when the Guru themselves authors profound spiritual works, such as the Shri Dnyaneshwari. The second, more common method is when the Guru inspires devotees to write their biographies. Service is then accepted through the study and performance of Parayans (devotional readings) of these biographies by both the writer and the wider congregation of devotees. As Chapter 0 explains, this act of study helps devotees achieve the purpose of their lives, and the writer gains merit for serving both the Guru and humanity.