Short Overview of Package Building Process
R packages can be built with the package.skeleton function. The given example will create a directory named mypackage containing the skeleton of the package for all functions, methods and classes defined in the R script(s) passed on to the code_files argument. The basic structure of the package directory is described here. The package directory will also contain a file named Read-and-delete-me with instructions for completing the package:
package.skeleton(name="mypackage", code_files=c("script1.R", "script2.R"))
Once a package skeleton is available one can build the package from the command-line (Linux/OS X). This will create a tarball of the package with its version number encoded in the file name. Subequently, the package tarball needs to be checked for errors with:
R CMD build mypackage
R CMD check mypackage_1.0.tar.gz
Install package from source
install.packages("mypackage_1.0.tar.gz", repos=NULL)
For more details see here