Photoshop or GIMP help

Anyone have a link to a tutorial on how to do automation (possibly called "batch" or "action") in either GIMP or Photoshop Elements? I have a layer (a signature) in Image A that I want to paste into 200 other images, resize, move into the corner, and save.

And while I'm asking, that layer is currently white and I want to change it to black. Man, there's so many things I've forgotten.