Here are the translation files of FreeCAD http://www.freecadweb.org
They include the FreeCAD interface itself, and the web homepage. The documentation is also translatable, but is handled directly on our wiki at http://www.freecadweb.org/wiki/
If you wish to translate FreeCAD in a language that is not listed below, just send a message to Yorik and it will be added.
Please note that due to the very technical nature of FreeCAD, and the necessity to understand well the different OCC concepts, we can only allow as proofreaders people with a substantial activity here or in the FreeCAD community. Thanks for understanding!