http://woordenlijst.org/ - excellent list of dutch words, especially good for people unsure of choosing 'd' or 't' ;)

http://www.interglot.com/ - dutch-english-dutch dictionary

http://dicts.info/ud.php?k1=1&k2=25&w= - english - dutch - english dictionary

http://www.vandale.nl/vandale/ - extensive dutch language dictionary and other language tools