Shanghai is a great place for street-shooting. remember to visit the Shi Ku Men 石窟门 and Li Nong 里弄 architecture. there's an artists' hangout at this place called Tian Zi Fang 田子坊 . Nanjing Road Pedestrian Street 南京路步行街 is the main shopping spine but you can always visit Hengshan Road 衡山路 for bars, cafeteria, cosy eateries, al fresco dining etc. 'M on the Bund' has a beautiful interior and a spectacular view of Huangpu River. always take care of your belongings when there, make sure you have everything infront of you (i.e. don't use your back pockets) and travel light. other than that it's a pretty enjoyable place that's easy to go around once you get accustomed to the local transit system. there're always the trusty cabs to fall back on when in need. a good command of mandarin will be useful. if you know Shanghainese that'll be even better.
You're probably in Shanghai already, but in case you've not noticed it so far, its REALLY hot in Shanghai nowadays. I woke up this weekend at 6am to take photos and its already hot. If you want to take a picture of the sun rise over Pudong at the Bund, you better get there before 6am. I'm guessing 5:30am at least.