This 100-page digest-sized booklet was grandly called The Official Starlog Communications Handbook Volume 1. It was published in 1979, and edited by David Hirsch with introductions by Bjo Trimble and an article by Eileen Skidmore. There was no volume 2.
This was a resource for fan letter writing. There were short chapters on starting a fan club (from Eileen, who ran the Nick Tate club), and how to write a fan letter, a mixture of fan letters to Starlog magazine, some never published before, and a directory of studios and fan clubs (the regular magazine also ran "yellow pages" sections in several issues with the same content).