Originally Posted by moondog
1. buy a guide book
2. read it (not necessarily cover to cover; just try to develop a decent understanding of your options)
3. try to figure out where you want to go
4. buy a plane ticket (into Beijing, out of Shanghai works for most people in your boat, but you might find that your interests are different)
5. if have specific questions at any point, feel free to post them here
however, regarding #5, it is expected that you do some legwork on your own before seeking advice on ft.
I second Moondog's advice....china is a big place and impossible to see all. It would help us to help YOU if you do some initial research and study, and then tell us where you'd like to visit (eg Beijing, Shanghai, Yangtze River ride???), how much time you have to visit, approximate budget requirements (so that we don't give you the wrong hotel recommendations), etc.
As a starter, if you haven't already, I would recommend getting started on your Hep A and B vaccinations. Not just for China but if you are traveling internationally, it's always good to be up-to-date on these two diseases. You can get more info re vaccines, etc. by reading cdc.org and/or search through my previous posts.
good luck and hope to hear back from you