Once you've learned some basic Mandarin vocabulary, watching Mandarin movies can be an enjoyable way to practice your language skills. As you can see on the Internet Movie Database, there are lots of Mandarin movies available. DVD's usually have optional English subtitles, so watch the movie once with the subtitles to get the story, then watch it again without the subtitles to see how much you can understand.
If you've ever seen some of the low-budget Hong Kong productions on late-night TV, you might get the idea that Chinese movies are all second-rate, but there are plenty of good Mandarin films. The best Chinese films are honored each year at the Golden Horse Awards. The winners of the 2008 awards are listed in this Variety Asia article.