Just completed three weeks in China.
Had set up a taxi thru references on FT, was a no show at Beijing !
I went to the info desk in arrivals, requested the young lady to please write down the name and address of my hotel, ( in English on my res confirmation)Courtyard Marriott...took her more than 20 minutes and phone calls. Strange, I kept on pointing to the name and address in English but she just wanted to call....it took THREE cab rides as the first two took us to the wrong Marriott.
After that I haerance.tnd shop at the hotel staff write in Mandarin my next hotel.
Look up your res con. And see if your hotel will send you a Chinese version.

Re GW, best bet is to have a cab or private car take you there. Average about 700 CNY. if you can share it, better.
Hope the pollution and haze will be a lesser problem for you.
Depending on your health get a walking stick ( folding about 8 USD at the