Check out Slate's complete coverage of the Beijing Games.
Where can I see the authentic Beijing? Which one? The one that was artificially suspended in the 1960s by the Cold War? Or the one being artificially accelerated into the 21st century? The authentic Beijing is synthetic—a composite of the edicts and aspirations of centuries' worth of different Chinese rulers. When Marco Polo got here, by his account, Kublai Khan had just relocated the entire population to a new city, built right next to the old one, on the advice of an astrologer.
With that in mind, look for the real Beijing the way you'd look for an authentic Chinese restaurant: Watch where the Chinese people go. It may be disappointing to see crowds flying kites or dancing on some charmless, overscaled plaza outside an office/retail complex—or pedaling bicycles through an overrenovated, Disneyfied hutong. But that's the city they live in.
If you want to see what things looked like before they got fixed up, have a look at the north bank of the Tonghui River, just outside the Second Ring Road below Jianguomen. There, a strip of charming squalor has somehow missed demolition or renovation: Low, grubby brick buildings huddle in a row, with stray bricks holding their roof coverings in place. Keep this scene in mind as you see citizens strolling through narrow, lushly planted roadside parks around the rest of the city—the sod and trees mark the graveyards of similar rundown stretches.
What should I eat? Beijing duck is one of the world's great chauvinistic local delicacies, like pizza in New York or pizza in Naples. After you've eaten duck in Beijing, when you go to a duck house somewhere else and get decent strips of meat wrapped in an OK pancake, all you will taste will be your own tongue, which you will be furiously biting to avoid jabbering on and on about how much, much better the real thing is.
Snub recommendations of the duck at Quanjude (overrated, for tourists) and at Made in China (too cute, for oversophisticates). Get it done fancily at one of the two branches of Da Dong, or un-fancily at Xiangmanlou.
Beyond the duck, there are two indigenous branches of cooking: imperial, which can be fussy and bland, and old Beijing, which is pungent and filling. Imperial is served in prettier dining rooms, but all the rest of the advantages belong to old Beijing. Have some zhajiangmian—noodles tossed with bean sauce and minced pork—and a side of ma dofu, a gray paste of the fermented dregs of tofu-making, fried in lamb fat.
Two warnings for diners accustomed to American Chinese restaurants: Restaurants in China hold back the rice till the very end of the meal, so it doesn't compete for stomach space with the meats and vegetables. And in China, takeout containers are hopelessly flimsy—loosely closing clamshell boxes made of something that combines the water resistance of paper with the structural strength of thin-gauge plastic.
What should I do about money? Despite Visa's obligatory pre-Olympic inroads, credit-card coverage at Beijing shops and restaurants is spotty. ATMs, however, are plentiful. Withdraw a bunch of 100 RMB notes and start breaking them with coffee-shop or convenience-store purchases as soon as you can. Not only does Beijing run on cash, but at the low end of the spending scale, it runs on small bills. Handing a 100 to a snack vendor (or a cabbie) can get you anything from resentment to outright refusal.
If you get a 50 in your change, hold it up to the light. A watermark of Mao's face should appear in the white space on the left front of the bill, and in a circle next to the white space, you should see a geometric figure, half-ink and half-shadow, neatly aligned. That tip won't save you from all the counterfeits, but it will at least spare you the embarrassment of passing a crudely made one.
Among your small bills will be some that are literally smaller—undersized bills denominated in jiao, or tenths of RMB. These went from being an annoyance to a convenience when China outlawed free plastic shopping bags this year, requiring merchants to charge a nominal fee before bagging your goods.
How do the taxis work?
A glowing red sign on the dashboard or up by the windshield indicates an available cab. If the drivers won't stop, you may be standing in a no-pickup zone—search the area for an official cab stand, or try a side street.
The chance of getting a cabbie who can speak fluent English is, optimistically, 1 in 500. (Many drivers, in from the provinces, don't even speak particularly good Mandarin.) In taxis, as elsewhere in the service sector, Beijing's push for remedial foreign-language instruction has trained people to converse the way automated voice-recognition phone trees do—stray at all from a narrow script, and you're stuck.