What are the different ways a devotee can serve their Guru through books or written texts?

Chapter 0 explains that a Sadguru accepts two primary types of service from devotees through books. The first is when a Guru, like Shri Dnyaneshwar, creates a great work themselves. The second, more accessible to devotees, is when the Guru has their biography written by a follower. This act allows the writer to perform Guru service through the process of creation. Furthermore, other devotees can then perform service by studying this biography and conducting Parayans (devotional readings). This benefits both the reader and the original author, who gains the merit of serving God in humanity (Jan-Janardan).