The woods are full of articles about carbro and carbon printing (that is
the circa 1904-to-1940 woods). For updates try, in addition to the list
archive, which has, among other information, several step-by-steps and
some trouble shooting, Luis Nadeau's book on carbon printing. I don't
have the exact title in front of me, but it's the only one I know of in
print, and available from most photo book outlets.
Also, Klaus Pollmeier gives a very fine workshop on carbon printing (among
other processes) in picturesque Germany, with complimentary Black Forest
cake. (Well I don't know for sure about the cake -- just a suggestion,
Klaus). If there are any on this continent, someone is bound to let us
know...
cheers,
Judy