Old, current, and worth the read!
I am currently rereading the Flavia de Luce series and it only gets better! I have purposely read them out of order. Although, I agree, starting with the first book is a must.
I think you would enjoy reading the Sharyn McCrumb's Ballad series. Start with She Walks These Hills. They are Appalachian historical mysteries.
Wow, thank you so much! This is a great list and I'm honored to be on it.