English Idioms and Idiomatic Expressions

http://www.usingenglish.com/reference/idioms/

Longman English Dictionary

http://www.ldoceonline.com/

Cambridge Dictionaries

http://dictionary.cambridge.org/

Urban Dictionary

You may find that certain expressions aren't on a regular dictionary. That's because it's slang. So here you have a link for those times when wordreference is not enough.

http://www.urbandictionary.com/

About writing - Very useful material

I've found this list of files that I reckon are really useful in order to prepare for the written part of the exams. You have some layouts for different types of letters, and also check lists and words of advice.

http://blog.educastur.es/awweoio/downloads/

The Bob and Rob Show

http://www.thebobandrobshow.com/website/index.php

Listen and Read Along

On this site, you can read and at the same time you can read what is being said.

http://www.manythings.org/listen/