The d3 Javascript library allows us to make beautiful, interactive browser-based data visualisations. By joining standard web page elements with a well-formed data set, d3 enables us to create everything from simple bar charts to complex infographics. d3 leverages existing web technologies, allowing the data scientist to create graphics using HTML and SVG, and to style them using CSS. This book guides a practitioner through the first few steps of learning d3 through a set of tutorials, based on real-world publicly available data from the New York Metropolitan Transit Authority.