General courses:

http://www.mansioningles.com/

http://www.learnenglish.de/

http://www.saberingles.com.ar/songs/index.html

http://www.learn-english.co.il/

http://www.britishcouncil.org/learnenglish.htm

And specially:

http://www.bbc.co.uk/worldservice/learningenglish/

http://www.agendaweb.org/

Dictionaries:

http://www.wordreference.com/es/translation.asp

http://dictionary.cambridge.org/

http://dictionary.reference.com/