I ran across a little treasure trove of Victorian culture. Sohie Lagace is an engineer by day and a role player by night. One her favorite games is Castle Falkenstein with its Steampunk setting. She has a webpage called "The Salon" that has links to all sorts of Victorian fashion, etiquette, culture, language and technology. Here are just a few of the links:
Victorian Slang Glossary Speech of the Lower Classes
How to Speak Proper Slang for the Upper Classes
The Library Victorian Science, technology, military history, etc.
The Salon is a labyrinth well worth exploring. (Don't worry, you won't get lost.)
Link to the Salon webpage
[6-28-2014 update: The Salon seems to have vanished. The first three sites I mention are still there.]