I recommend you to listen to this website http://www.bbc.co.uk/worldservice/learningenglish/language/theenglishwespeak/  "The English We Speak" which is from BBC. This website has useful idioms and you can learn these with interesting and funny story, each story is about 3 minutes. What's more you can download as Podcast, so we can listen to them wherever we are. I believe you'll enjoy them.