Can you travel across China via train?

Are trains common in China?
For a project, I need to get from China to Dunhuang by train. Are there any sites that I can get some info or something equivilant to travelocity

Yes.
Try this link from SideStep as an example.

travelling by train in china needs tons of patience.You have to buy the ticket several days before.What's more, on the train, there is a lot of thieves, so keep your valuable bags in hand.anyway, I would rather recommend that travel by plane is faster , safer and cleaner,even though not environmental friendly.DUN HUANG is a great place to go.You can fly to XI'AN first and take a train to DUN HUANG>
enjoy your trip.

Yes, the train is the main mode of transportation for China. Ut has gotten better over the years but over the holiday season, it can still get extremely crowded. So note, don't travel over the holiday season.

Check out the web sites below, they are in Chinese, with prices and & time of departure/arrival.

yes

no

Yes you can, but unfortunately you can't get one ticket that covers all legs of travel like with the Eurorail. The best bet in this situation is to contact a travel agent, your hotel will usually have this service (in China) or z-visa.com they can arrange for this type of service.

If you expect long trips on the train, don't fool with seats, get hard or soft sleepers according to your budget. Anything more than 4 hours on the train is long..

If you are making intercity connections (for example from Beijing to Tienjin, Hangzhou to Shanghai, Guangzhou to Shenzen) then a bus is your best option.. If travelling from Beijing to Hangzhou or Shanghai, trains vary but can take from 12 to 23 hours. If time is a constraing, domestic airfare is pretty reasonable, between 800 - 1900 rmb one way from Xian/Beijing to Shanghai / Guangzhou or Hong Kong.. Thats $100 - $250 each way.. Trains are going to cost about $50 for the hard sleeper (a cot with six berths) to $80 Soft sleeper, Private room, four berths..