General R command syntax

object <- function_name(arguments) 
object <- object[arguments]

Finding help

?function_name

Load a library/package

library("my_library")

List functions defined by a library

library(help="my_library")

Load library manual (PDF or HTML file)

vignette("my_library")

Execute an R script from within R

source("my_script.R")

Execute an R script from command-line (the first of the three options is preferred)

$ Rscript my_script.R
$ R CMD BATCH my_script.R 
$ R --slave < my_script.R