On the early morning, you could take a train (1 hour) at Shanghai South Railway Station or a bus (2 hours) from Shanghai South Bus Station to Jiashan firstly. These two stations are located at the same place in Shanghai. When you arrive in Jiashan, there are many buses could be used here driving you to Xitang in 30 minutes with a fare of only 3.5RMB. You could use the same way to back to Shanghai in the afternoon.