Thomson Reuters has published a new report called "Patented in China: the Present and Future State of Innovation in China." Patent filings from China have been growing faster than any other region in the last few years and if the trend continues it will become the "dominant country in the patent landscape" by 2012. The press release and PDF report are available at http://scientific.thomsonreuters.com/press/2008/8494659/.
The EPO's East Asian Patent Information portal has a number of FAQs and guides to Chinese, Korean and Japanese patents.