I am looking for step by step instructions or a ready made action for
photoshop CS to do what I describe in the next paragraph.

The action should work with the batch processing command. The action
will find the file name of the image (just the short file name such as
"Image001.jpg", not the longer file location) and superimpose the file
name in Black 14pt Ariel Rounded Bold in the bottom left corner of the
image (there could be 25 pixil margins on the left and bottom edges if
that makes things easier. Then the action will save the image file
with the same name and in the same place as the original file (it will
overwrite the original
file).

I'm pretty good with Photoshop, I just can't figure out how to do this.

In advance thank you for your help.