I am a firm believer in teaching base R before moving onto the tidyverse, and Norm Matloff’s post on Teaching R in a Kinder, Gentler, More Effective Manner is spot-on.
John Bentley's great bumper-sticker bits of programming wisdom.
A fantastic cross-reference of operations in R, Python, and Matlab/Octave by Vidar Bronken Gunderson. [archived]
Common statistical tests are linear models by Jonas Kristoffer Lindeløv
Rob Hyndman’s Twenty rules for good graphics
A good explanation of why you should use natural logs on betterexplained.com
Writing R Functions. Some sound advice.
New York Times article on the growing use of R, from 7 January 2009. Thanks to Scott Gifford for finding this!
Max Pekarsky on The Overflow, on writing code other people can read.
FiveThirtyEight on why scientists have difficulty explaining p-values.
A follow-up by Nate Silver on the problems with p-values.
Nature on the problems of p-values.
AGU's EOS forum (24 November 2009, v. 90, no. 47) on statistical significance, geological significance, and the problem with p-values.
XKCD on Tufte. Hover your mouse over the comic for Tufte.
XKCD about the misinterpretation of p-values in the popular press.
XKCD on curve fitting and the messages they send.
XKCD with a modified Bayes’ Theorem.