Great R: Level 1 will teach you the fundamentals of R, from the basics of using the software as a calculator through creating your own data objects and visualizing them. By the time you're through these lessons, you'll be able to load your own data into R and evaluate it using R's native functions.
Throughout the course, you'll progressively learn to analyze data using R's fundamental data structures: vectors, data frames, arrays, lists, and factors. You'll also learn to write your own functions and plot your data using R's powerful graphics utilities. Finally, you'll try out some mind-blowing visualizations from the famous lattice package.