Most of these sites offer American English. It's pity there aren't any British English sites!

The BBC's Children's News has hundreds of stories, all of which you can listen to. Some of the vocabulary will be difficult so why not open the Cambridge Learner's Dictionary, too and then put them side by side so you can drag difficult words from the news into the dictionary. Here is a picture of what it looks like.

New!
The BBC offers a huge range of web pages that could be useful for anyone learning English who has reached the level of upper-intermediate.

I had a quick listen to some of these interviews with people like Elijah Wood, Britney Spears, Johnny Depp. I thought the quality was fantastic with broadband (ADSL) and the content might appeal to you. The interviews are also relatively short 5-10 minutes.
http://www.bbc.co.uk/radio1/jowhiley/interviews/

Another thing I saw that I thought might be interesting is a new experimental chat on the BBC. The idea is that once you have signed up you can browse around a lot of pages and ‘meet’ other people who are looking at the same pages. I didn’t bump into many people but I was there at 10 o’clock in the morning on a Sunday UK time, when most young people are probably still in bed! Anyway, my username is chris_bcn
http://www.bbc.co.uk/communicate/connector/

News is a good source of listening material as it is updated every day. The BBC’s Newsround, which is for children has three advantages over the normal news or the World Service news. The first is that there is a recording of the vast majority of the news items and the second is that they are short and the third is that the voices are much younger and more like the sort of voices you might like to imitate!
http://news.bbc.co.uk/cbbcnews/

Another more difficult and longer source of listening is the Live Chat archive. Here you will find much longer interviews some of which you can see on video as people like Pet Shop Boys, Mis-teeq, but many are just text and less useful.
http://www.bbc.co.uk/communicate/archive/

Finally, the vast collection of short videos on Video Nation is great practice for listening as the videos are homemade and only a minute or two long. It’s a pity there are no transcripts, but you can use the slider to listen again to bits you don’t understand straight away. There are a good range of accents and ages.
http://www.bbc.co.uk/videonation/archive/
If you find this too hard, there are a dozen or so videos with transcripts and exercises here.