Coming to China is easy enough - get a visa and fly over. While it's a little bit of an inconvenience having to apply for a visa, the process is quick and easy. It takes just one day to get it, and you can even request rush processing to get the visa in a few hours if needed. I settled in Shenzhen, and the easiest way to get here is to fly to Hong Kong
(no visa required) and then take a minibus to the China border.
The regular tourist visa lets you stay for up to 30 days and has one or two entries. A business visa is valid for six months. I believe there are also visas for longer periods but that option wasn't available in the application form last time I applied. I didn't bother finding out more since it's easy to get a new one anyway. In any case, at least my latest business visa still required me to exit China every 30 days (and then turn back and immediatelly return for a new period). It's a minor inconvenience, but at least gives me a good reason to visit Hong Kong once a month.
Neither the tourist nor business visa actually gives you a permission to work, but start and own a business as long as you're not employed by the company. This gives you an opportunity to get the business process going quickly and worry about the paperwork to get the work permit later on.
This map shows Shenzhen, which is located in south China, across the border from Hong Kong. That's where I currently reside, writing this blog as we speak!