Based on the preface, what are some recommended practices for devotees to engage with a Guru's teachings and build a community?

A primary way to engage with a Guru's teachings and foster a community is through the study and devotional reading of their biographies. The preface explains that a Sadguru accepts service from devotees through books. This can involve devotees writing detailed, comprehensive biographies, or the congregation of devotees studying and performing Parayans (devotional readings) and Saptahs (week-long readings) of these works. As mentioned in chapter 0, when devotees study and perform Parayans, the writer gains merit for serving "God in humanity" (Jan-Janardan), and the other devotees also achieve the purpose of their lives, creating a shared spiritual practice.