I find China way more accepting and open to photography than here. As in any venture, be respectful (you are in their country, after all) and you'll be fine. I've made 5 trips there and never had an issue once.
I did use a Lonely Planet book to learn the Mandarin phrase for "May I take your photograph?" and that with some good humour seemed to open doors.
Film is best if you bring it, but can be found in Beijing and Shanghai at the camera malls. Haven't seen the one in Shanghai but the one in Beijing is pretty amazing.
Dont' forget a currency/voltage converter!