I just wanted to share a few sources of the information that I am finding. Some things are easier to get a hold of than others, but it makes for a fun search.
Books:
Hair Its Diseases and Treatments by C. Henri Leonard pub. 1879
Victorian Ladies Hair Care and Grooming pub. 1896*
Water Waving by Evelyn Frederick pub. 1923*
Marcel Waving Flapper Hairstyling Techniques pub. ~1930*
Hairstyle Design by Louis Maryberry pub. 1946*
The Mystery of 1950s Hairstyling by Comer and Doran pub. 1955*
Ingerid's Alphabet of Curls by Miss Ingerid pub. 1962
How To Handle Long Hair Book I and II by Miss Ingerid pub. 1954 and 1957*
Creative Hairstyling and Hairshaping You Can Do by Ivan of Hollywood pub. 1947*
How It's Done...Hairstyles For You by Ivan of Hollywood pub. 1948**
10 Hollywood Hairstyles and How To Do It Yourself by Arlene Dahl pub. 1952***
The Professional Way To Set Your Own Hair by Jack of Westwood pub. 1946****
Vintage Hair Styles of the 1940s: A Practical Guide by Bethany Jane Davies pub. 2016
Vintage Hairstyling: Retro Styles with Step-by-Step Techniques by Lauren Rennells pub. 2009
1940s Hairstyles(Vintage Living) by Daniel Turudich pub. 2012
DVDs:
Vintage-Inspired Up-Styles - The Collection, Anje Kastner Studios
The Lost Art of Vintage Hair, Patrick Cameron-2012
YouTube:
AVintageVanity
LisaFreemontStreet(lisafreemontstreet.blogspot.com)
Glamourdaze(glamourdaze.com)
Tristan
Vintage Fashions(British Pathe)
British Movietone
Historia-Bel99TV
Online:
beautyisathingofthepast.blogspot.com
Etsy shop - schmetterlingtag(shop has many reproductions of vintage books)
lekeux.com
*Copies of these books can be found on the scmetterlingtag Etsy shop
**Digital copy available at http://catalog.hathitrust.org
***ebook can be found on Glamourdaze.com
****Reproduced as 1940s Hairstyles You Can Do by C. Franzwa for letsplayhistory.org