R_Statistics introduces you to R
In the lab we have the book Using R for Introductory Statistics.
There is a wiki with some good tips here.
Examining your data matrix or object, let's say it's called datos
Don't use the function attach. It seems to leave lots of data in the 'environment' that can cause problems later. Also it makes the code harder to understand.
doing ANOVAs etc
Dealing with circular data
von Mises vs. wrapped Gaussian,see Swindale, N. V. (1998). Orientation tuning curves: empirical description and estimation of parameters. Biol Cybern, 78(1), 45-56.