First off, China's a big place, you have to figure out what part of China you really want to know about. I'm assuming you want to know about traditional culture and not today's pop-culture and commerce. Try looking through Wikipedia; it's becoming more and more accurate.
First, look up "China," then, click on the links that look interesting to you. You didn't specify what exactly you want to know and why, and you didn't even say if your "Asian friends" are even Chinese, so that's the best I can suggest.
