How to write R package

Hi List,
Would you please send me a good link to talk me through on how to write a R
package?

See the ?package.skeleton help page.  After you have run it, follow the 
instructions in the "Read-and-delete-me" file that it will create.

For full details, see the Writing R Extensions manual.

For modifying the package after you've finished the "Read-and-delete-me" 
instructions, just manually add *.R files where the rest of them are, 
and use the prompt() function to produce skeleton documentation.

That's about it, but you can read more if you like in a tutorial I gave 
a few years ago at a UseR meeting in Dortmund:

http://www.statistik.uni-dortmund.de/useR-2008/slides/Murdoch.pdf

Duncan Murdoch