How to add a border:
Firstly, open up the image you want to add a border too.
Once opened, unlock the layer by double-clicking the layer name.
I'll be using this..
Now you to want go to the bottom of the layers palette and click
on the Create A New Layer
icon highlighted in red.
Highlight Layer 1, use the Pain Bucket tool and fill it in with blk.
Go to the Layers Palette and select the Layers Style icon highlighted in Red.
A vertical list will drop, select Stroke.
I'll finish this later.