Swirl is a package for R that turns the console into an interactive way to learn R programming and data science concepts. It starts from basic R to much more in-depth and advanced topics. Users are able to learn new concepts and immediately put them into practice by answering questions. You are also given immediate feedback, which is very helpful for more difficult concepts. It is completely free and the instructions for how to get started can be found here: swirlstats.com/students.html.