There are probably many ways to do this. Personally, I created an action for this.
I'll say this from memory, as I don't have PS on this machine.
- You open an image and go to the "Action" tab (next tab after the "History" tab).
- Press the Record button (little red circle) (can't remember if you have to assign a name then or at the end. If now, then call it 'watermark' or 'copyright'...)
- Go to the Text tool and select the font and size to use.
- Write your copyright onto the picture.
- Apply any effect to this (e.g. change in opacity, warping, etc.)
- Merge the layers (Layers>Merge Visible)
- Press the "Stop" button in the Action tab
At this point, the action is recorded, and you can either use it manually on other pictures, or automate by going into the File > Automate menu
There you have to select the action to apply (i.e. "Copyright"), the folder where your photos are, and where to save the new files).