Do some research on ergonomics to help you learn how to set up your computer station so that you are less likely to sustain injury while typing. Repetitive stress injuries such as carpal tunnel nerve syndrome are very real and extremely painful. You should use both hands to type, but make sure your keyboard, monitor, desktop, and chair are all at the right height and angle for your body. You can also get wrist supports to help keep your wrists in the correct position while typing. If you have pain, a visit to your chiropractor does wonders. I have my wrists adjusted every time I go to the chiropractor, since I spend many hours every day on the computer.