http://www.wikipedia.org
The Free Encyclopedia.

http://www.interglot.com
Very useful dictionary on the Internet (From Dutch to French, English, Spanish, Swedish and German or otherwise).

http://www.bahn.de
The best train planner of Europe; die Deutsche Bahn AG!

http://www.9292ov.nl
You go by public transport in the Netherlands? Find your way here!

www.google.com
No need to explanation.

http://www.youtube.com
No need to explanation.

http://www.map24.com
Very useful road map.

http://www.cia.gov/cia/publications/factbook/
CIA factbook; if you want to know something from a country, the CIA will help you!