I am using ubuntu 14.04 LTS. When I open a Chines web page, for example, this in Firefox, I got all crazy symbols. How to ask Firefox to display Chinese correctly, please? Could anyone provide a step by step guide, please? Thank you!
That particular web page is the problem. If you check the source (Ctrl+U), the only character set (charset) encoding specified is GB2312. Firefox won't detect it automatically.
Nowadays, most web sites intended for international viewing should use Unicode (UTF-8) for compatibility. For example, if you check:
you should see normal Chinese text. If you check the source (Ctrl+U), near the top of the page you will see: charset=utf-8
In Firefox, you can select a different character encoding in the View menu. You would have to check those listed as Chinese to see if the text is legible.