What is a Visa?

A Visa is a "pre-authorization" stamp inside your passport.

How do I get a visa?
You can obtain an application at the Chinese embassy or consulate in your home country.  You should generally apply for a visa one to two months before departing to China.  You need to appear in
person at the embassy or consulate closest to you.  You will need to return at a later date to pick up
the completed visa or to deal with any problems which may arise.  If you cannot appear in person,
you can authorize a courier service to apply in person on your behalf.

What will I need to apply for a visa?
A complete application form for a visa obtained from the Chinese Embassy or Consulate.
You will need two 2"x2" photos of yourself, a current passport with more than two blank visa pages remaining
in it, and documents explaining your reason for traveling to China.
You may be asked to show evidence of your exit travel in the form of air, rail, or ship tickets.