If you want a book of wittily-written anecdotes based on the tradition that N. American English and British English are "separated by a common language," then BRITISH LANGUAGE & CULTURE isn't quite your thing because it doesn't spend a lot of time on past usages. Nor would you want it if all you want are the common slang and idiom of bygone days, to help you when reading the Bronte sisters or Kingsley Amis.
What you get instead -- and I am so glad someone thought to do it and do it so well -- is a 255-page, up-to-date phrasebook of British to American. Just as thorough and comprehensive as a good pocket (Berlitz-style) phrasebook of German, French or Spanish into English. This is the place for thousands of British locutions, idioms, terms for everything from food to sporting events to cinema-going, street slang, the most wounding swear words and their approximate force upon impact, even greetings and phrases inherited from Welsh, Irish (via Liverpool) and Scotland.
Do you think you'd like the dish called "Toad in the Hole," and is it quite proper to inquire about the availability of "Spotted Dick"? If you needed a bus to Oxford should you to go the bus station -- or the coach station? Is "High Street" something like a scenic drive? This volume is so rich in usuable words and phrases, you can even use it to get out of trouble (even to get you into trouble if that's your yen). Sometimes, and IMHO at the right times, the authors step in with a few sentences of context, history and shades of meaning in actual usage. "British" isn't always as precise as we Yanks might think!
This compact volume is reasonably well bound (it was printed in China) and small enough for the smallest shirt pocket. The colored pages and the color-keyed indices thereunto are downright beautiful, and more to the point, helpful and speedy. This may just be the only contemporary guide to modern Brit you'll need for a trip. There are lots of other books that are wittier and show more history. BRITISH LANGUAGE & CULTURE isn't precious but it is smart, and 100% helpful.