Techyard.net supplies you with goodies of quick and dirty wp plugins. One of that interest me is that this plugin already serves the purpose of providing English, German, Simplified Chinese languages to your wordpress blog. Presenting qTranslate that currently comes with those 4 said already built-in languages. No more tiring, tedious coding of .po and .mo, here’s how to manually do it.

http://codex.wordpress.org/Installing_WordPress_in_Your_Language

http://codex.wordpress.org/WordPress_in_Your_Language

—
You can also add a new language to the plugin by entering the 2-Letter ISO Language Code.

Check out the Installation guide on how install the plugin.