97 Cavalier noises

Hey guys, i finally got a video of my engine running....This video is of the engine without A/C on. The microphone on my camera can't really pick up the noise over the engine, but the belt makes this clicking noise you can hear slightly...

http://www.youtube.com/v/RVvPu8g7Xq4

yeah just wondering if anyone would know what it is, and how easy it would be to fixxed. Heard Serp. belt but where is that located, and how easy is it to install.