This is sort of a follow up to my previous blog post on fontconfig, and also part of my efforts in making the EeePC a simple-to-use and pretty (in my own view) PC.
With such a small screen and fonts, complicated Chinese characters will be rendered as unintelligible white space with black dots when using Sung/Ming fonts (宋体，明体). In this case, Gothic/Hei fonts (serif equivalent to East Asian font) are very readable as it is capable to be rendered even with small font sizes. In this case, WenQuanYi's Zen Hei is the best open source Gothic/HeiTi font (and I even highlighted it in one of my post).
For this setup, I make it more simplistic: Copy a good template which specifies preferred Latin fonts (e.g. /etc/fonts/conf.d/60-latin.conf in Debian) to ~/.fonts.conf. Once that's in place: paste <family>WenQuanYi Zen Hei</family> in each <prefer> section.
Once that's in place, execute `fc-cache -fv` and restart your applications, and TADA! browsing Chinese sites on Firefox has never been more enjoyable with unified and readable text :D.