All Languages
Computing with Accents, Symbols, and Foreign Scripts - Information by Language - from Penn State University
Non-English Keyboards Macintosh OSX- from Penn State University
Developing Non-English Websites - from Penn State University
Asian Languages
Computing in Japanese - from Penn State University
Type Chinese Using the Microsoft Office Suite - Windows XP and Office 2002 (pdf)
Type Pinyin Using Microsoft Word (pdf)
Configuring the Multilingual Capacities of Windows XP (Chinese) (pdf)
European Languages
Le Notepad - Just click to input accented letters. (French only).
Making International Characters in Windows. (French, German, Italian, Spanish).
Making International Characters on a Mac (French, German, Italian, Spanish).
The Microsoft Visual Keyboard (pdf) allows you to easily use the Russian (and other) keyboards.
More coming soon.