There are utilities out there that do batch renaming. Try searching VersionTracker.com and MacUpdate.com
Next is a question of what you want to rename, and what you want to rename it to. That affects the code.
If you are going the Unix shell scripting route, you have to be careful about spaces in names, as Unix commands are parse on white space boundaries, and so a file name with a space in it may look like 2 files, neither of which exsits. So quotes are needed to prevent that.
Automator and Applescript are uses to spaces in filenames, you just have to master their usage. There are actual forums for Applescript
<http://discussions.apple.com/forum.jspa?forumID=724>
and Automator
<http://discussions.apple.com/forum.jspa?forumID=1261>,
which might be more helpful.
