I used 'package.skeleton()' to generate .Rd help files a few months ago. I have edited these files, and I have also changed the functions, removed some functions, added others. Is there a function that automates updating the Rd files?
update
A nice package was just released called Rd2roxygen, it is described by the author Yihui Xie on his blog.
As the name implies, this package allows one to retroactively insert documentation currently contained in .Rd into .R files. Sounds like a promising approach for both learning roxygen and for converting packages currently in development to R packages. Woo hoo. Thanks Yihui!
Based on answers by Joshua and Yihui, the answer appears to be: roxygen allows automatic updating of Rd files etc based on changes in the source .R code, and if I am not using roxygen currently, Rd2roxygen can help me migrate.