The JavaScript Library d3.js is a powerful tool for interactive data visualizations. It allows you to easily connect your data to an HTML document and add interactive functionality on top of it.

Links

• A comprehensive API reference is hosted on GitHub.
• The website has many examples and documentation about the tool.
• A free book about d3.js and also some JS fundamentals can be found here.
• There is an udacity course for d3 as well.
• Another course can be found here.
• A fast and condensed tutorial has been made by square.
• A short cheatsheet with all the important functions is available here.
• Some cool video tutorials can be consumed here.
• There are also some slides by the creator of the library.
• A highly interactive workshop that let's you code from the start is located here.
• There is a nice website that explains data grouping.