Annnd . . . what do I think so far? What a fun set of characters! Of course, that can be said of all the Georgette Heyer books I've read. She has amazing diversity of personality and backstory for the cast in each book.
Something I appreciate is that while the books are all historical romances set in Regency and Victorian times, the women protagonists are strong personalities (Yes, I've noticed a little chauvinism here and there and some very outdated stereotypes, but let's not assign this year's moral standards to decades or centuries past) and accomplished in their own right--hard to do considering the times those women are set in.
When I started reading these, I was only going to read one. But I couldn't stop. Here are my favorites in no particular order (Beauvallet, Venetia, Fredrica, Devil's Cub, The Grand Sophy, Arabella):
1. This genre has some very specific requirements and it's a good idea to check with the publisher or agent you want to pitch to for those expectations before you send in a finished manuscript. (Confession--I wanted to read The Grand Sophy because it was recommended to me when I asked how to improve a romance Deanna and I have and couldn't stop.) These guidelines will tell you the number of words to shoot for and how much physical intimacy is tolerated or expected.
2. Considering your future submission also gives you parameters for the ages of your lead characters (the ones who are "sitting in a tree k-i-s-s-i-n-g")
3. The beginning and the end are somewhat predictable: At the beginning they meet or see each other and although there is some kind of connection, they know it just wouldn't work. The end is when they get together and the reader knows they will be together in the future.
There are some great online resources for writing romances as well as national organizations like the Romance Writers of America.
To internalize this type of story structure, maybe the best advice in this case is read, read, read! And why yes, I do have some great recommendations.