Translating docs is a breeze: Just hit up the Tools menu, select Translate document, then choose the language you want to translate to. Docs will open the translated document in a new window, then offer to replace the original document with the translation or copy the translation to a new document. It’s probably not for everyone, but it’s a nice feature, nonetheless, and yet another example of Google’s continued march toward integrating its various services.
Translate documents: sharing across languages and generations [Official Google Blog]