Cash Renminbi is easily obtained via cash machines in Beijing - most will work with cash cards from overseas. However some will not. The Bank of China works well as does the Communications Bank. Normal receipts are dispensed so you can save them. The daily limit from your own bank may dictate how much you can pull out every 24 hours.

Credit cards including Visa, Mastercard and American Express can be used to get cash too if you are set up to do so and are widely accepted by hotels, larger restaurants and shops. For more local venues such as souvenir markets you will need cash.

Cash and well known travelers checks such as American Express can be changed in large hotels and most banks (some banks don't do foreign exchange). The Friendship Store also does foreign exchange.

If you have an American Express card you can go to the Bank of China with a personal check from your home country bank and get a lot of cash out at once. For instance on my gold card I could pull out US$2500 (only once every seven days I believe) and get the money in cash US$ or changed into Renminbi. Various American Express cards have differing limits, check with Amex before departing for details.

You can also get lots of cash out with other credit cards at the Bank of China, check with your card company for exact details.

The exchange rate is approximately US$ 1 = RMB 8.27 and is more or less locked to the US dollar.

There used to be a black market for foreign exchange but that seems to have disappeared.

Learn to recognize Chinese currency and speak about money related matters in Chinese here