I moved to Beijing in October 2012. Here is a growing list of advice and links passed along to me from various expats in Beijing.
The Beijinger – This website is so fucking annoying. It’s slow and cluttered with useless ads. However, it has free classifieds and seems to be the only way foreigners buy/sell stuff to each other.
Maps and Directions – I prefer Baidu’s maps. They seem to be the most accurate (better than Google) and have a great mobile app. Requires some fooling since it’s in Chinese, but you should try it. I can’t read Chinese very well and still figured it out.