1. Sharon H. Laudermilk and Teresa L. Hamlin, THE REGENCY COMPANION
A truly great introduction to the everyday life of the upper classes in the Regency era. Unfortunately, the book is not only out of print, but also hard to find, thus sellers of used books can demand exorbitant prices. (Duh.)
2. Ben Weinreb and Christopher Hibbert, editors, THE LONDON ENCYCLOPAEDIA
Very few illustrations, but lots and lots of great information. All you've ever wanted to know about London, past and present.
3. Hugh Montgomery-Massingbred and Christopher Simon Sykes, GREAT HOUSES OF ENGLAND AND WALES
Need to build a country estate for your characters? Here you find descriptions and a vast number of gorgeous photographs of 32 stately homes, from Alnwick Castle to Waddesdon Manor.
4. Michel Saudan and Sylvia Saudan-Skira, FROM FOLLY TO FOLLIES: DISCOVERING THE WORLD OF GARDENS
Well, if you've pieced together a country estate for your characters, you'll also need a garden. Here you find descriptions and pictures of different kinds of European gardens and garden architecture.
5. Steve Parissien, REGENCY STYLE
A true treasure trove for everybody who writes novels set in the Regency. Parissien covers everything from architecture, windows, and plasterwork to colours, fabrics, furniture, and gardens. Contains many illustrations and photographs.
6. Akiko Fukai, FASHION: A HISTORY FROM THE 18TH TO 20TH CENTURY: THE COLLECTION OF THE KYOTO COSTUME INSTITUTE
What can I say? Your characters need clothes, too! And in this book you'll find pictures and descriptions of the most beautiful clothes (dresses, mostly) imaginable. This is an awesome book!
7. Shelley Tobin et al., MARRIAGE À LA MODE: THREE CENTURIES OF WEDDING DRESS
In a romance novel, there's bound to be a wedding. This publication of the National Trust describes dresses and wedding customs from the mid-18th to the 20th century, and contains many contemporary illustrations and photos as well as pictures of wedding dresses from the collections of the National Trust.
8. John Seymour, FORGOTTEN HOUSEHOLD CRAFTS
Have you ever wondered how people in the 19th and early 20th century made butter or cheese? How they dealt with the dirty laundry? What their lamps looked like? How they kept their homes clean? John Seymour answers all of these questions and many more. He provides a fascinating glimpse at household chores of ages past.
9. THE REMINISCENCES OF CAPTAIN GRONOW
Tee-hee! Full of anecdotes from the years 1810-60.
10. MRS BEETON'S BOOK OF HOUSEHOLD MANAGEMENT
A great resource! Mrs. Beeton doesn't just give the reader a list of recipes, but also includes advice about how to run a household, about the duties of the different types of servants, and about caring for the ill. Even though it was first published in the Victorian era, it can be a valuable source for earlier time periods as well. The full text of the book is available online at mrsbeeton.com.
11. A. E. Richardson, THE OLD INNS OF ENGLAND
A survey of historic inns across England. If your characters ever need to travel and you want them to stay the night somewhere on the road, this is the book for you!
12. Lesley Blanch, editor, HARRIETTE WILSON'S MEMOIRS
More reminiscences about the Regency era, yet this time we get a glimpse at society from a female point of view. What's more Harriette Wilson was one of the most famous courtesans of the early 19th century -- she knew all the important men of London. And in her memoirs, she named names.
13. Patrick Hanks and Flavia Hodges, A CONCISE DICTIONARY OF FIRST NAMES
Well, your characters don't just need country estates, gardens and clothes, but also names! In this book you won't just find a list of names, but also a few lines about the meaning, history, and use of each name.