If you have not yet had a chance to try “R” as a language, here is a good site for having a go at some of the functions and power of the R programming language.

Code School – Try R

There are 8 lessons in this group

1. Using R
2. Vectors
3. Matrices
4. Summary Statistics
5. Factors
6. Data Frames
7. Real-World Data
8. Whats Next

The lessons present you with an R interface so you don’t have to have the R software installed on your end device.

There are also other good lessons available from http://www.codeschool.com such as Try GIT and GIT Real.