Beijing official website: http://www.ebeijing.gov.cn/

Beijing wiki: http://en.wikipedia.org/wiki/Beijing

Beijing Capital International Airport: http://en.bcia.com.cn/

Beijing Subway: map   http://www.ebeijing.gov.cn/feature_2/Subway_Tour/

Beijing Bus: http://www.bjbus.com/

Weather: http://www.weather.com.cn/en/

Travel Agencies:
http://www.chinatraveldepot.com/
http://www.cits.net/