Practical, User-Friendly, Introductory "How-To" Book Suggestions for R

A colleague determined to conquer R (or at least become functionally fluent) bemoaned recently R's inaccessible documentation and obtuse manuals. To be sure, the price is right (R is free open-source), but she is now looking for suggestions on helpful, basic, and more user-friendly "How-To" books for R. As this is the Holiday season I agreed to pass along her request. Suggestions (and comments) welcome.

Comments

[Eric Rasmusen]

I discovered R last fall and was charmed by it. A wonderful language, with incredibly bad documentation tho. I wrote up the basics of how to load data and do everyday regressions here for my senior undergrad class (and myself!) here:

http://www.rasmusen.org/a/r.htm

[SeanCK]

John Fox's "An R and S Plus Companion to Applied Regression" is a good introduction to R. It's focused on regression and linear model packages, but most of the lessons are also applicable to other packages.
http://www.amazon.com/Plus-Companion-Applied-Regression/dp/0761922806
But you could probably also learn R using only free internet resources. This is where I would start.
http://cran.r-project.org/manuals.html