R is a powerful language and environment for statistics and scientific graphics. Some of the main advantages of R is that is free/open-source and users can find a lot of help online. RStudio provides free interface to R that has an organized layout and many extra options for R users. The slides below give an overview to the R language, and they provide instructions on downloading and installing R and RStudio, as well as, showing some of the main features of RStudio.
Included in these slides are links to YouTube videos, which cover R and RStudio installation most operating systems, including: Windows, Mac OSX, and Ubuntu Linux. Furthermore, the videos cover how to install and configure Java for R so that users can make use of the rJava package, which is used by many R packages; rJava allows package developers to make use of existing software written in Java that can oftentimes be faster than code written in R. Proper installation of rJava requires the manual installation of the 64-bit version Java. By default, the main Java download page gives users a 32-bit version of Java that will not work.
After installing R, beginner users should read this Introduction to R.
Slides: Install R: http://slides.lunean.com/uspWorkshop/installR.pdf