John Bear's R checklist

Cheat Sheet: Tom Short's Cheat Sheet

The Best Online R Textbooks  Statistics Textbooks Online
Introduction to the R Project for Statistical Computing for use at ITC  by Rossiter   (PDF)
The R Guide by Owen   (PDF) Introduction to Probability and Statistics Using R by Kearns    (PDF)
simpleR – Using R for Introductory Statistics by Verzani   (PDF) Practical Regression and Anova Using R by Faraway   with R examples    (PDF)
An Introduction to R by R's Core Development Team (HTML) Introduction to Statistical Thought by Lavene (43MB)   with R examples   (PDF)
An Introduction to R: Software for Statistical Modelling & Computing
by Kuhnert and Venables   (4.5 MB zip file) MyLocalPDFCopy
Introduction to Probability by Grinstead and Snell   with Matlab examples   (PDF)

R Graphics Textbooks
R Graphics by Paul Murrell   (HTML) Put a call to browser() in the function of interest.
Using R for Data Analysis and Graphics
Introduction, Code and Commentary by Maindonald
After an error message try traceback()

Try binary search

Web Search (only if you must) R help functions apropos('regexp') # Search for loaded symbols (functions, etc.)

help(functionname) # Tells how to use the function
For Hard Questions'regexp', agrep=F) # Search the help system database fields
Official R Manuals'pattern') # Search help db using Levenshtein edit distance
Frequently Asked Questions library() # Shows loaded packages
Highly annotated indexes of R packages: CRAN Task Views library(packagename) # Loads the package
Other Contributed R Documentation vignette('packagename') # Overview of package

ls(package:packagename) # Functions in package

ls() # Shows currently defined local functions & variables

search() # shows things on the search path

args(functionname) # Shows the names of the function's arguments