Listening is something students (here in Spain at least) typically find difficult. Here are three sites that will provide teachers with material for class and students some practice at home.
My favourite is http://www.elllo.org/ This site has an enormous collection of people speaking “real” English about all the typical topics people actually talk about. Many of the people featured are students so there is something for all levels. There is also video material and tasks and tapescripts to go with the listenings. It is worth spending time surfing this site and it is quite extensive.
http://www.eslvideo.com/ is another site full of material for most levels. The videos have tapescripts and also quizzes. You can even make your own quiz for a video if you want to be adventurous.
This site http://es.yappr.com allows you to watch videos and read a tapescript in both English and Spanish. Very useful and the videos are varied with many uptodate topics and themes included.
Probably more suitable for higher levels is http://www.ted.com/ a site which features talks on a variety of subjects given by famous people. Even if not suitable for your classes you will probably enjoy it yourself!