Here are some of the websites and books that I turn to most frequently when editing and translating. Perhaps you’ll find something useful here too.
Van Dale's Dutch/English dictionary. It’s so much quicker to search the online version than to leaf through a paper dictionary.
One of my favourite experts on language is R.L. Trask. His book on punctuation, The Penguin Guide to Punctuation, is clear, readable and incredibly useful.
Strunk and White’s is a classic, and a great resource when writing in American English.
Two books on the everyday use of Dutch that complement one another rather nicely: B.C. Donaldson’s Beyond the Dictionary in Dutch (organised alphabetically in English) and Kevin Cook’s Dubbel Dutch (organised alphabetically in Dutch).
The EU’s IATE multilingual terminology database is extremely useful for finding word equivalents in all EU languages.
The Nuffic Glossary is an indispensable site for Dutch-English academic and education-related terminology.