Shanghai to Huangshan is about 7 to 8 hours by train (take the overnight train on "soft berth"; you'll sleep like a baby). It's very touristy, so very easy to climb, with gondolas being available and trails extremely well maintained and well identified. The lack of challenge is made up for by the beauty of the scenary though. It's absolutely magnificent. Just make sure you go there on a cloudy day, so you can marvel at the "sea of clouds" under your feet and the peaks of mountain jetting out.
Very near Huangshan is Jou Hua Shan (sp?), which is one of the holy mountains. I've never been, but it's it's supposed to be very beautiful. And spiritual, if you like that sort of thing.