Free resources for learning R I'm interested in learning R on the cheap. What's the best free resource/book/tutorial for learning R?
 A: The official guides are pretty nice; check out http://cran.r-project.org/manuals.html . There is also a lot of contributed documentation there.
A: If you're an economist/econometrician then Grant Farnworth's paper on using R is indispensable and is available on CRAN at:
http://cran.r-project.org/doc/contrib/Farnsworth-EconometricsInR.pdf
A: If you have experience in other languages, these "R Rosetta Stone" videos may be useful:


*

*Python

*MATLAB

*SQL
These are all included in the video list added by Jeromy, so big +1 for his list.
A: One resource is 'Some hints for the R beginner' at
http://www.burns-stat.com/pages/Tutor/hints_R_begin.html
A: I have written a document that is freely available at my website and on CRAN. See the linked page:
icebreakeR
The datasets that are used in the document are also linked from that page.  Feedback is welcome and appreciated!
Andrew
A: After you learn the basics, I find the following sites very useful:


*

*R-bloggers. 

*Subscribing to the Stack overflow R tag.

A: A large number of short videos that cover a lot of useful tasks with R (91 videos as of March 2013): http://www.twotorials.com/ 
Here's a nice new interactive online tutorial on the basics of R: http://tryr.codeschool.com/
A: Some useful R links (find out the link that suits you):
Intro:

*

*for R basics http://cran.r-project.org/doc/contrib/usingR.pdf

*for data manipulation http://had.co.nz/plyr/plyr-intro-090510.pdf

*http://portal.stats.ox.ac.uk/userdata/ruth/APTS2012/APTS.html

*Interactive intro to R programming language https://www.datacamp.com/courses/introduction-to-r

*Application focused R tutorial https://www.teamleada.com/tutorials/introduction-to-statistical-programming-in-r

*In-browser learning for R http://tryr.codeschool.com/
with a focus on economics:

*

*lecture notes with R code http://www.econ.uiuc.edu/~econ472/e-Tutorial.html

*A brief guide to R and Economics http://people.su.se/~ma/R_intro/R_intro.pdf
Graphics: plots, maps, etc.:

*

*tutorial with info on plots http://cran.r-project.org/doc/contrib/Rossiter-RIntro-ITC.pdf

*a graph gallery of R plots and charts with supporting code http://addictedtor.free.fr/graphiques/

*A tutorial for Lattice http://osiris.sunderland.ac.uk/~cs0her/Statistics/UsingLatticeGraphicsInR.htm

*Ggplot R graphics http://had.co.nz/ggplot2/

*Ggplot Vs Lattice @ http://had.co.nz/ggplot/vs-lattice.html

*Multiple tutorials for using ggplot2 and Lattice http://learnr.wordpress.com/tag/ggplot2/

*Google Charts with R http://www.iq.harvard.edu/blog/sss/archives/2008/04/google_charts_f_1.shtml

*Introduction to using RGoogleMaps @ http://cran.r-project.org/web/packages/RgoogleMaps/vignettes/RgoogleMaps-intro.pdf

*Thematic Maps with R https://stackoverflow.com/questions/1260965/developing-geographic-thematic-maps-with-r

*geographic maps in R http://smartdatacollective.com/Home/22052
GUIs:

*

*Poor Man GUI for R http://wiener.math.csi.cuny.edu/pmg/

*R Commander is a robust GUI for R http://socserv.mcmaster.ca/jfox/Misc/Rcmdr/installation-notes.html

*JGR is a Java-based GUI for R http://jgr.markushelbig.org/Screenshots.html
Time series & finance:

*

*a good beginner’s tutorial for Time Series http://www.stat.pitt.edu/stoffer/tsa2/index.html


*Interesting time series packages in R http://robjhyndman.com/software


*advanced time series in R http://www.wise.xmu.edu.cn/2007summerworkshop/download/Advanced%20Topics%20in%20Time%20Series%20Econometrics%20Using%20R1_ZongwuCAI.pdf


*provides a great analysis and visualization framework for quantitative trading http://www.quantmod.com/


*Guide to Credit Scoring using R http://cran.r-project.org/doc/contrib/Sharma-CreditScoring.pdf


*an Open Source framework for Financial Analysis http://www.rmetrics.org/
Data / text mining:

*

*A Data Mining tool in R http://rattle.togaware.com/

*An online e-book for Data Mining with R http://www.liaad.up.pt/~ltorgo/DataMiningWithR/

*Introduction to the Text Mining package in R http://cran.r-project.org/web/packages/tm/vignettes/tm.pdf
Other statistical techniques:

*

*Quick-R http://www.statmethods.net/

*annotated guides for a variety of models http://www.ats.ucla.edu/stat/r/dae/default.htm

*Social Network Analysis http://www.r-project.org/conferences/useR-2008/slides/Bojanowski.pdf
Editors:

*

*Komodo Edit R editor http://www.sciviews.org/SciViews-K/index.html

*Tinn-R makes for a good R editor http://www.sciviews.org/Tinn-R/

*An Eclipse plugin for R @ http://www.walware.de/goto/statet

*Instructions to install StatET in Eclipse http://www.splusbook.com/Rintro/R_Eclipse_StatET.pdf

*RStudio http://rstudio.org/

*Emacs Speaks Statistics, a statistical language package for Emacs http://ess.r-project.org/
Interfacing w/ other languages / software:

*

*to embed R data frames in Excel via multiple approaches http://learnr.wordpress.com/2009/10/06/export-data-frames-to-multi-worksheet-excel-file/

*provides a tool to make R usable from Excel http://www.statconn.com/

*Connect to MySQL from R http://erikvold.com/blog/index.cfm/2008/8/20/how-to-connect-to-mysql-with-r-in-wndows-using-rmysql

*info about pulling data from SAS, STATA, SPSS, etc. http://www.statmethods.net/input/importingdata.html

*Latex http://www.stat.uni-muenchen.de/~leisch/Sweave/

*R2HTML http://www.feferraz.net/en/P/R2HTML
Blogs, newsletters, etc.:

*

*A very informative blog http://blog.revolutionanalytics.com/

*A blog aggregator for posts about R  http://www.r-bloggers.com/

*R mailing lists  http://www.r-project.org/mail.html

*R newsletter (old)  http://cran.r-project.org/doc/Rnews/

*R journal (current)  http://journal.r-project.org/
Other / uncategorized: (as of yet)

*

*Web Scraping in R http://www.programmingr.com/content/webscraping-using-readlines-and-rcurl

*a very interesting list of packages that is seriously worth a look http://www.omegahat.org/

*Commercial versions of R @ http://www.revolutionanalytics.com/

*Red R for R tasks http://code.google.com/p/r-orange/

*KNIME for R (worth a serious look) http://www.knime.org/introduction/screenshots

*R Tutorial for Titanic https://statsguys.wordpress.com/
A: The R project website has lots of manuals to start, and I suggest you the Nabble R forum and the R-bloggers site as well. 
A: If you already know another programming language, these notes may help point out some of the ways R might surprise you.
A: I liked these lectures: Statistical Aspects of Data Mining. The lecturer is solving example problems using R.
A: If you are coming from a SAS or SPSS background, check out:
http://sites.google.com/site/r4statistics/
This is the companion site to the book, R for SAS and SPSS Users by Robert Muenchen and a free version of the book can be found here.
A: One more:  R bloggers has many posts with tutorials materials:
http://www.r-bloggers.com/?s=tutorial
A: If I had to choose one thing, make sure that you read "The R Inferno".
There are many good resources on the R homepage, but in particular, read "An Introduction to R" and "The R Language Definition".
A: There are some very good learning materials here: http://scc.stat.ucla.edu/mini-courses/materials-from-past-mini-courses/spring-2009-mini-course-materials/
A: Look for R Users Groups in your area.  They are growing around the world.
http://blog.revolutionanalytics.com/local-r-groups.html
If you don't have one then help get one started.  I'm sure you will be able to find like minded interested folks.
As for helpful links the Dallas R Users Group has a nice list.
http://www.meetup.com/Dallas-R-Users-Group/pages/R_Helpful_Links/
A: http://www.datamind.org offers interactive R tutorials, currently focused at real beginners
A: Quick-R can be a good place to start.
A little bit data mining oriented R and Data Mining resources: Examples and Case Studies and R Reference Card for Data Mining. 
A: *

*If you like learning through videos, I collated a list of R training videos.

*I also prepared a general post on learning R with  suggestions on books, online manuals, blogs, videos, user interfaces, and more.

A: Try IPSUR, Introduction to Probability and Statistics Using R. It's a free book, free in the GNU sense of the word. 
http://ipsur.r-forge.r-project.org/book/index.php
It's definitely open source - on the download page you can download the LaTeX source or the lyx source used to generate this. 
A: If you'd like a beginners tutorial to R in the context of Econometrics this may be a good starting point as well: http://www.quandl.com/learn/working-with-quandl-and-r
