R

R is a statistical program/environment that can be used for statistical modeling or analysis. More information about R can be found on its About page on its homepage.

Apart from the excellent documentation that can be found on R project's page, below are some of the links that I find useful.

• UCLA Academic Technology Services page related to R
• Prof. D. G. Rossiter's page (See under "R applications")
• Hadley Wickham's pages related to R and other statistics courses he teaches
• Advanced R -- by Hadley Wickham (a very useful resource!)
• Geographic Data Analysis Using R
• How R Searches and Finds Stuff -- very useful
• My R related notes
• My R related utils developed over the years

R Intro (pdfs)

• Introduction to the R project for statistical computing for use at ITC -- by David Rossiter
• Using R for data analysis and Graphics: Introduction, Code, and Commentary -- by J H Maindonald
• R for beginners -- by Emmanuel Paradis
• simpleR - Using R for Introductory Statistics -- by John Verzani
• Practical regression and Anova using R -- by Julian J. Faraway

If you cannot avoid using Excel

Patrick Burns's "Spreadsheet Addiction" lists some common problems associated with Excel. He also has many tutorials pertaining to R under the "Tutorial" title on his page (link).