Idioms galore!

This year we'll be learning a lot of idioms in class. Here you have links to three good idioms websites.
1.- A large collection of idioms listed alphabetically, with brief definitions: http://www.usingenglish.com/reference/idioms/
2.- A selection of "self-study idiom quizes" with answers: http://a4esl.org/q/h/idioms.html
3.- A website explainig the origins of dozens of popular idioms: http:// www.idiomsite.com/