How can followers of Sai Baba perform 'Guru service' through books?

According to the preface in Chapter 0, a Sadguru accepts two types of service from devotees through books. The second, more accessible form of service is by having biographies written and then accepting service through their study. Therefore, devotees can perform Guru service by studying and performing Parayans of a detailed biography. The text specifically points to the 'Shri Sai Satcharita' by Annasaheb Dabholkar as the ideal work for this purpose, noting that engaging with this text is a direct way to serve the Guru and deepen one's connection.