How a person on social visit to Singapore can get tourist visa for China ?

I and my wife are Indian Passport holders. Currently, we are on a social visit with our son, Sanjeev Joshi in Singapore, where he is employed in. We are permitted to stay with him till Feb.24, 2012.
He wants to take us to China (main land) sometimes in 1st or 2nd week of Feb.2012, where he (Sanjeev) too will be visiting. He is ready to bear the travel cost, hotel charges, etc. on our behalf. But, we are unable to furnish our own financial details, for being out of India.
Please let us know the procedure to obtain travel visa.