This book is a guide on how to build a community network, a shared local telecommunications infrastructure, managed as a commons, to access the internet and other digital communications services. It was written collectively by a group of community network pioneers in Europe, activists and researchers during a writing residency week held in Vic, Catalonia in October 2018. It was a time of hard work and fast writing, but also of discussions in a friendly environment. Meant for a wide audience, the book includes practical knowledge illustrated by several hands-on experiences – a set of 32 real-life stories – as well as legal, technical, governance, economic and policy material extracted from netCommons, a three-year-long research project supported by the European Commission. Its goal is to guide the reader through a set of actions aimed at setting up and fostering the growth of a community network, but also, for policy makers, local administrations and the general public, to create the right conditions to let community networks bloom and flourish.