Hi everyone -
If you're learning R for the first time and know SAS or SPSS, you'll
find this site very helpful:
http://sites.google.com/site/r4statistics/free-version
The author, Bob Muenchen, wrote a book called "R for SAS and SPSS
Users" which I used to learn R and found very helpful. He has a free,
short version of the book on the website available. It covers the
basics of data management from a practical and easy to understand
perspective.
Hope this helps!
-Michael