An Introduction to R
Notes on R: A Programming Environment for Data Analysis and Graphics
W. N. Venables, D. M. Smith, R Development Core Team
This introduction to R is derived from an original set of notes describing the S and SPlus environments written in 1990–2 by Bill Venables and David M. Smith when at the University of Adelaide.
Also available in html: http://hackershelf.com/book/180/an-introduction-to-r/