train ticket concern

I'm planning to visit China's UNESCO WHS such as BJ and surrounding, Chende, Taishan, Qufu, Qingdao, Yungang caves, Wutaishan, Pingyao, Xian, Songshan and Dengfeng, Luoyang and Longmen caves, (Huangshan, if enoguh time) etc. Likely to start from Jan 1st 2012 for 5 weeks.

I'm concern of been stuck by Chinese Spring Festival on Jan 23rd. Does anybody know when train and bus tickets start to be very difficult to get because of that Chinese new year?

any suggestion is appreciated,
thanks,
Young