This how-to tutorial covers the creation and publication of free online books using the bookdown package in R, including chapter organisation, cross-referencing, and deployment to GitHub Pages. It is aimed at researchers and educators in linguistics and the humanities who want to publish course books, long-form documentation, or research monographs as open-access online resources. This tutorial is part of the Language Technology and Data Analysis Laboratory (LADAL), a free, open-access research infrastructure at the University of Queensland. LADAL provides tutorials, tools, and courses for researchers working with language data. All materials are freely available at https://ladal.edu.au and are part of the Language Data Commons of Australia (LDaCA), funded by ARDC and NCRIS.