If you have a large number of files and you need to rename them, you are able to use the 'rename' command:
In the following command, I rename all of my video files from 00-99 to 000-099, this is so that they are listed in order when I have over 100+ video parts:

rename part part0 part[0-9][0-9].mp4

More information (ignore the link name, an example in the forum uses 'rename': http://stackoverflow.com/questions/2372719/using-sed-to-mass-rename-files