1. Put any C/C++/Fortran code in ‘src’
2. If you have compiled code, add a .First.lib() function in ‘R’ to load the shared library
3. Edit the help file skeletons in ‘man’
4. Run R CMD build to create the index files
5. Run R CMD check to check the package
6. Run R CMD build to make the package file

Read “Writing R Extensions” for more information.