The American duchess (18thc dressmaking and 18thc beauty) books are helpful for the 18thc. Regency women's dress https://www.amazon.com/dp/B015FWL7MC/ref=dp_kinw_strp_1 Also this book Dress in the age of jane austen has info on both men's and women's clothing. https://www.amazon.com/Dress-Age-Jane-Austen-Regency/dp/0300218729
Hope that gives you a good start! Welcome to the world of historical clothing :) Please keep us updated on you creations and progress!