R Programming for Data Science by Roger D. Peng [free download Choose "You pay $0" or higher amount if you wish to donate.]
Writing code and setting your working directory on the Mac [YouTube, 7:41 minutes]
Writing code and setting your working directory on Windows [YouTube, 7:19 minutes]
R Nuts and Bolts, Data Types [YouTube, 31:05 minutes][PDF]
Getting Data In and Out of R [YouTube, 5:51 minutes][PDF]
Subsetting R Objects [YouTube, 4:13 minutes]
Managing Data Frames [YouTube, 15:30 minutes][PDF]
Scoping Rules of R [YouTube, 10:31 minutes]
