Watch videos which will teach you the basics of the German language. The BBC German video series (see Resources) will help you to develop a foundation in German-speaking and become used to hearing the language spoken. Watch the introductory videos, and try and to understand what is taking place. Watch them a second time, and try to pick up individual words. Download the transcripts and read along with the videos.
Watch more advanced videos as you begin to improve. Get videos which are not designed for language learning to gain an appreciation of colloquial German. Choose a TV show which you enjoy and watch this in German. Although it will seem daunting at first, you will soon be able to pick up on phrases. The more you watch the more you will understand.
Watch videos of the news in German. This will contain formal language, which can be hard to understand, although you should persevere. Often, if the news is based on the same news stories as English-speaking news, you will be able to gain an understanding of what is happening. If you have the news on video, rewind and watch sections again, which will help with your comprehension. Again, it will take some time before you can understand fully what is being said.