The following are free online resources for learning how to use and troubleshoot R. Many more resources can be found online, including an R-specific search engine can be found at rseek.org and R section of the question-and-answer site Stack Overflow.

• Introducing R, by Germán Rodríguez

  A readable and gentle introduction to basic concepts for R.

• An Introduction to R, Notes on R: A Programming Environment for Data Analysis and Graphics, by W. N. Venables, D. M. Smith and the R Core Team

  A manual for using R written and maintained by the core R development team. Provides extensive detail, possibly too much for someone first wading into the software.

• Population Health Data Science with R: Transforming data into actionable knowledge, by Tomás J. Aragón

  A comprehensive open-source e-book that provides the basic for epidemiological analysis using R.

• Impatient R, by Patrick Burns

  General reference tool for basic ideas and concepts in R.

• R Inferno, by Patrick Burns

  Help identifying problems that will haunt you in R. Useful for looking up why something has gone wrong or unexpectedly in R.