Do you want to graft those roses onto another type of rose, Sara, or do you just want to propagate cuttings from that huge rose? I ask because many rosarians prefer own-root roses to grafted types (although grafting is essential in Florida because of nematode issues). This article from the University of Georgia Cooperative Extension Service will give you the full rundown on taking cuttings:
I am sure that she means propagate it I am sure there is good information in the link Doug gave. Nope guess not because I am getting an error.