The best websites I’ve ever used to buy plane ticket is http://www.ctrip.com. They are actually a public company listed on Nasdaq. One caveat is that they don’t accept overseas credit card. You’ll have to have a friend in China to buy it for you, or you can one a China credit card with Bank of China (中国银行）. Otherwise you can also buy domestic tickets with China Travel Service (中国旅行社), although they are a little more expensive. With an e-ticket, you can check-in by showing your ID without printing anything.

On ctrip you’ll usually find that most tickets are discounted at over 50-70%. It can cost as low as $380 CNY to travel from Shenzhen to Shanghai one way + tax ($150) ,ie total $530CNY. 中国旅行社 might cost you around $700. If you buy ticket from HK to Shanghai, it can cost well over $1000 HKD one way. So if you travel to China often, you can save alot of money by going through Shenzhen.

To book for hotels, there’s koubei.com or kooxoo.com. If you want to have a look at the surroundings, you can use edushi.com, which has 3D virtual worlds of most major cities. It will be alot easier if you use a China credit card to book for hotels. For $200/night, you can find decent rooms for business use.