Google Translation is
reasonably accurate but, as with any other translation website, you should always 'reverse translate' everything. If translating from English to Dutch, and then back again, gives exactly the same phrase or sentence that you started with, then there's quite a good chance that you've found an accurate translation. However if you get something very different it would be best to assume that the first part of the translation is at fault.
The first search engine to introduce translations (as well as the first to have image searches and lots of other innovations) was the mighty AltaVista. [Google simply copied all of AltaVista's ideas). Alas, AltaVista is no more; it was taken over by Yahoo! However the translation site is still there, and still one of the best, as Babelfish:
http://www.babelfish.com/
Babylon is also surprisingly accurate:
http://www.babelfish.com/
Imtranslator is handy because it can automatically 'back translate':
http://imtranslator.net/translation/english/to-dutch/translation/