Originally posted by: puffff
If you dont want to wade through my blog, I'll can give you some suggestions here. First spend more time in Beijing than Shanghai. There's more to see and more to do in Beijing. One day is enough to see the Forbidden City/Tianamen Sq. Its worth making the trip to see the Temple of Heaven too. Yonghe Lamasery is good for another half day, the Summer Palace will take at least a whole day by itself. See the Great Wall, try to go to the Jinshaling/Simatai sections of the Great Wall, avoid Badaling and Mutianyu unless you have no other choice. Those are the musts, there are a lot of smaller landmarks around that you can fill in with too.
Shanghai, spend a day or two on the Bund. Two towns nearby make for interesting day trips too, Suzhou and Hanzhou. See Yuyuan Gardens and the area nearby. I'd say that makes up the highlights of Shanghai.
Oh, and when you're in Beijing, dont forget to try Peking Duck. It's cheaper there than anywhere else in the world, and it's delicious!