I can try to give you a little run through...
Ok, first open just some sample image. Make sure you can see the Actions Palette (it's usually with History Window-->Actions)
Click the "Create New Action" on the palette, name it, and click ok.
It starts to record everything you do and save it as the action.
From there just resize as normal... (Image-->Image Size...) and Save it
And when you're done click Stop in the palette, and you're basically done
When you want to use it, open the next image you want to resize, and, with your action selected, click Play, and it'll run through the resize automatically and then prompt you for the save settings
To expedite it even more, you can File-->Automate-->Batch, and you should be able to figure it out from there
🙂
Hope that helps,
reality