How to run a recorded action on a folder of images?

The last time I used Photoshop was in 1998, and things have changed a bit. I'm sure if I had time to read all the documentation I could figure out how to do this, but I'm under an extremely tight deadline and the guy who would normally do image processing is on vacation.

I have a folder of more than 500 images. I need to change the height, width, and resolution of all of them. I know how to record an action that I can then run manually on open images, but is there any way to run that action on a folder of images without having to open all of them? It could take years if I need to open them before running the action.