This guidebook, the first of its kind, summarizes the state of the art in the field of epistemic gossip protocols. Gossip protocols are peer-to-peer communication protocols intended to maximize information dissemination while respecting network or transmission constraints. This comprehensive reference begins by presenting classical results on gossip protocols from networks and combinatorics from the 1970s and progresses through results in distributed computing up to the work on epistemic distributed gossip protocols of the past decade. In epistemic gossip protocols, agents make information-based choices to speed up information dissemination and allow smarter and more involved forms of distributed communication. Topics covered include various call semantics, reachability of secret distributions, dynamic gossip where secrets and numbers are exchanged, optimality, protocol knowledge, and higher-order epistemic goals. Featuring numerous exercises, this book from a lead researcher is an ideal resource for graduate students and researchers in logic, computer science, artificial intelligence, and cognitive science.