This book provides a step-by-step approach to the use of R software. R is an open source programming language and software environment for statistical computing and graphics, and is widely used by statisticians for developing statistical software and data analysis. R is freely available under the GNU General Public License and pre- compiled binary versions are provided for various operating systems. R uses a command line interface. This manual is intended to serve as a self-teaching resource for health science researchers, who shy away from biostatistics and its analysis by statistical softwares. An explanation to the statistical concept is provided prior to the R demonstration. A beginner can start with the exploratory data analysis and then step up to the advanced areas.