R is leading data analysis software and programming language. It has capacity to handle moderate to large dataset and creating publication ready graphs. This manual is designed as self-help manual useful beginner to more advanced users, with some statistical and computing knowledge. The author hope this manual will be useful for several areas of biological sciences including genetics, molecular biology, genomics, bioinformatics, biotechnology, agriculture, plant science, botany, ecology, breeding, animal breeding, systematics, animal science, human biology, human health, biomedical sciences, environmental science, microbiology, biochemistry and physiology. Examples and r scripts are provided to cover these areas of biological science. Software can be downloaded for free from: www.r-project.org.