The website is About.com, which I guess complies articles or information about topics, that you can easily sift through or search for. It contains this article about the relationship between the United States and China, as well as many other articles about the United States' relationship with other countries, for instance at the bottom of the China article, it suggests that I look at other relationships between the United States and the United Kingdom for example. The article is set out in time periods, for instance the Korean War and the Second World War etc.
This article gives an overlook of the relationship of the United States and China, from beginning to the present. It even says "The disintegration of the Soviet Union re-inserted a tension into the relationship as both countries lost a common enemy and the United States became an undisputed global hegemon. Adding to the tension is China's rise as a global economic power and the expansion of its influence to resource rich areas such as Africa, offering an alternative model to the United States, usually termed the Beijing consensus." This paragraph is from the most recent time period, where it does include the fact that the United States has become a global hegemon, and the world has gone into a uni-polarity. It mentions the rise of China's global economy which has the power to overtake the United States. Though it has been argued that China will not become the global hegemon, as it's culture is not easily accessed as well as America's.
At the bottom of the article, as I've stated already, it suggests certain relationships to research, but it also gives links to related articles about China and the United States. Overall this website, was useful but it was very general. Though it does provide extremely good examples, the amount of information to really learn about the relationship it seems, needs to be researched more.