What is described as the most effective form of service through writing for achieving salvation?

The source material describes the best and most certain service for attaining the fruit of salvation as writing the biography of one's own Sadguru. As explained in Chapter 0, this should be done either by the Guru's command or through inner inspiration. The process involves not just writing but also personally studying it regularly, performing readings (Parayans) and weekly recitations (Saptahs) with a pure heart, unwavering devotion, and selfless love. This type of service is considered a service of the body and speech that does not interfere with one's family or worldly responsibilities.