BBC Learning English

Another great website for self-study is the BBC's site:
http://www.bbc.co.uk/worldservice/learningenglish/
I particular recommend the "Talking Business" section which is a great review of useful vocabulary for the telephone, meetings, negotiations etc. http://www.bbc.co.uk/worldservice/learningenglish/business/talkingbusiness/

Need inspiration?

Studying grammar and memorising vocabulary is one thing, but actually speaking with another person is another.
Here are some useful websites as written by the New York Times:

http://www.nytimes.com/2010/07/29/technology/personaltech/29basics.html?src=me&ref=technology