There is now a document called “Some hints for the R beginner” whose purpose is to get people up and running with R as quickly as possible.

Direct access to it is:
http://www.burns-stat.com/pages/Tutor/hints_R_begin.html

JRR Tolkien wrote a story (sans hobbits) called ‘Leaf by Niggle’ that has always resonated with me. I offer you an imperfect, incomplete tree (but my roof is intact).

Suggestions for improvements are encouraged.

And here is the link tree for the document (for your easy reviewing of the offered content) :

This page has several sections, they can be put into the four categories: General, Objects, Actions, Help.

General
Introduction
Blank screen syndrome
Misconceptions because of a previous language
Helpful computer environments
R vocabulary
Epilogue

Objects
Key objects
Reading data into R
Seeing objects
Saving objects
Magic functions, magic objects
Some file types
Packages

Actions
What happens at R startup
Key actions
Errors and such
Graphics
Vectorization
Make mistakes on purpose

Help
How to read a help file
Searching for functionality
Some other documents
R-help mailing list