This handbook is a condensed version of the Data Steward Network Starter Kit (Horton et al., 2023). It supports the creation, launch, and development of new professional and sustainable communities of practice in the field of data stewardship.Professional networks play a key role in the context of the Skills4EOSC Competence Centre Network, where they are considered tools for lifelong learning through peer exchange.This document brings together theoretical models and practical action points to help data stewards build and develop their communities effectively.