There really isn't one in Harbin, but you can find a special school in Harbin to study as a volunteer. You can also buy a Chinese sign language to teach yourself. But sign language is more than just reading books. Bi needs to communicate with the deaf. You can also download some videos from the internet to learn. If you really love it, you might as well come to Nanjing during the holiday, where you can take exams and have special teacher training.