Much of Cynthia's corsetmaking knowledge has come through many years of research and trial and error. There is no substitute for doing your own reading and investigation. Current beginners are lucky, because there are many more resources now. Here are some great places to start:
Books – You simply cannot beat books for costume research. Here is an Amazon list of a bunch of helpful titles. We have read many of these cover to cover. Many of these can be gotten through inter-library loan programs.
Facebook/Social Media – There are a number of corsetmaking and costuming groups on facebook that have excellent information.