International communication

Key considerations

Avoid the use of slang or colloquialisms;
Avoid abbreviations and mnemonics;
Avoid humor;
Use consistent terminology and phrasing (use words that have only one meaning; use the same word for the same meaning throughout);
Use international system of measurements;
Take care with grammatical structures, especially where the text is précised;
If in doubt as to which word to use, find out what the translations of the various words mean, and then pick the most appropriate one;
Take care of capitalization in case this has special significance in some languages (e.g. German).

Consider problems of keeping translations up-to-date
Extra time delay in getting updates done
Have documents translated in 'destination country', or at least checked by users in the native language (but don't let them alter the work themselves)

Make sure you are aware of the need for translation before starting the English document
Provide standard translations for standard terms
Try to talk to the people doing the translation

Consider using side-by-side or separate sections
Consider the different lengths of texts in different languages. (Especially important where pagination is critical in source language.)
With illustrations, consider numbers for call-outs and a separate (translated) table for explanatory text (assuming western languages)