Xah Lee, 2011-01-12
Richard Sears, a scholar on Chinese character etymology, spend 20 years to bring a chinese char etymology reference online. There, you can type or paste any chinese char and see the char's history back to several thousand years. His site is at: www.chineseetymology.org.
See also: 简体/繁體 字表 (Simplified/Traditional Chinese Characters List). You can copy char there and paste in his dict to see its history.
Also interesting is that he wrote some intro. The first i read is this: Why Study Chinese Etymology @ Source www.chineseetymology.org. The title is a bit misleading. It is actually a intro to char history.
Here's the basic history of char forms.
His other article is this: Chinese Language and Script @ http://www.chineseetymology.org/mandarin.aspx. This one is a brief almost random commentary about various chinese dialects and Japanese, Korean, Vietnamese. This article is rather not scholarly, and seems random and biased.
If you want more info about chinese, i'd recommend Wikipedia: Chinese language ◇ Written Chinese. There's enough material for weeks of reading, covering spoken language, dialects, writing system, their history, and modern stuff such as romanization systems, input systems, char encoding, etc.