When it comes to buying clothes and shoes, the Chinese use a system that is very similar to the one used in Europe (Continental sizing system) but is, in actuality, just slightly smaller. So, a man who wears a size 9 shoe in the U.S. or Canada, would wear a size 43 in Europe, 43.5 in China and a 8.5 in the U.K. and Australia. However, pants sizes are measured in inches. So if you wear a 34-inch waist pants in North America, you would ask for a size 34 in China (but the length would be measured in centimeters).
Here are my experiences shopping for clothes in Jinan, at department stores, street vendors, plazas, and small boutiques. From what I've read on the internet and heard from female teachers who have travelled more than I have, expat women have these issues all over China:
As far as women's shirts (and some dresses) are concerned, the sizing is not similar to Europe. China uses a highly variable Small/Medium/Large/Extra Large system similar to the one used for women's clothing in the United States. However, a Chinese Small is always much smaller than an American Small. I have shirts I brought with me from home that say Small, which are larger than the shirts I've bought in China that say Large. If you wear any larger than a Chinese Large in my city, you WILL have trouble finding shirts outside of specialty stores. Some stores have a decent selection of XL, but not many.
Bras that fit a Western woman are nearly impossible to find in Jinan. The sizing system is different here, and assumes a MUCH smaller waistline than naturally occurs on most Westerners. I've had quite a few frustrating hours trying on bras, and after giving up I was told by other female expats that I'll have to go to Beijing or order them online; Western women just aren't built as small as Chinese women, and our breasts sit differently on our chests even when we do lose weight. Also, well-made Chinese bras aren't any cheaper than those in the US.
Your information is correct as far as shoe and pant sizes go, though I've found shoe sizes above a Chinese 39 (American 8-9, depending on brand) and pant sizes above an American 8 to be hard to find. It's easy for a Western woman in China to feel like a fat cow, and I hope you get enough responses from female readers to devote more of the Guide to women's issues. If nothing else, you might want to encourage women preparing to teach in China to bring two weeks' worth of clothes, and plenty of undergarments, from their home country.