When you put your foreign bank card into a Beijing ATM it should give you the option to display English, or display both Chinese and English. There are various different methods the banks employ to let you select language. The Bank of China ATMs give the password screen in both languages, then on the select account screen, the options are given in two languages, English to the left, and Chinese to the right (pictured below right).
On the select account screen (pictured right) it is essential that you use the left buttons to select your account as this is what determines the language you will be using from that point on. If you mistakenly press the buttons on the right, you will be in Chinese from that point onwards.
Other banks, like ICBC, have a separate screen near the beginning of the process which lets you select your desired language (pictured below left). At the end of some ATM transactions you will be given the option to continue or take your card (pictured below right). This is because the transaction limits on most bank accounts is set pretty low. The maximum you will be able to withdraw in one request is about 2500 RMB, sometimes as little as 1500 RMB. You can press the continue button and try to get more cash out up to the ATMs daily limit. Most USA banks allow you about 5500 RMB per day, but this is controlled by your own bank.
As a result of the limits set on Chinese bank accounts and ATMs, you will often experience the hell of Beijing / China ATM usage. You will join a queue of people at the ATM with maybe one or two people ahead of you. However, each person will probably do multiple transactions, and often use many cards from many different banks before they have withdrawn their ideal sum of money. This can be very frustrating, or amusing, depending on how much sleep you've had.
There are a couple of other banks which may accept foreign cards around Beijing, namely HSBC and Citybank. These ATMs are extremely rare however. Other internal Chinese banks almost certainly will not process your overseas transaction.
The ATMs mentioned here dispense Chinese RMB currency. The money will be taken from your foreign bank account. It will be converted to your home currency at a quite reasonable rate usually. The commission and transaction charges will be dependent upon your own bank's policies. If you are using an ATM / Debit card, usually the charges are comparable to drawing money in your own country (e.g. Bank of America charges $3 per transaction, which is the same as if you used a non-Bank of America ATM in the US) If you are using a Credit Card, you are usually talking about a "cash advance" which can be extremely expensive depending on your bank and how long you take to pay back the money.
