Download binary from oracle: http://www.oracle.com/technetwork/database/database-technologies/r/roracle/downloads/index.html
The run the following command in r, substituting the file path:
setwd('xxxxx') # set to path of download
install.packages('ROracle_1.1-11.zip', repos = NULL)
Then load the library and use the package - you may have to change XXXX to whatever is in your TNS Names:
library('ROracle')
drv <- dbDriver("Oracle")
# NOTE: never store passwords in a saved script!!
con <- dbConnect(drv, "USER GOES HERE", "PASSWORD GOES HERE", dbname='XXX')
test connection:
dbReadTable(con, 'DUAL')
For anyone else having trouble installing ROracle, the installation instructions on CRAN are actually very good and the links appear to all be working at the time of posting this. http://cran.us.r-project.org/web/packages/ROracle/INSTALL