Hi,Welcome to this tutorial.
Today we will explain a very easy tutorial, How to put a frame on a photo.
The first is to open the photo, in my case is:

Well, once we open the photo Select> All and will select the entire image.
Now let Select> Modify> Border and insert the thickness of the edge. In my case 10 px.

Now we are left with a selected edge.
If quieremos finish the tutorial here, we can just press Ctrl + Alt + U and go testing with the Saturation to 100 and changing the tone, for we have left something like this.

If you want to make a complete edge when we have the choice of the edge we just have to press Ctrl + J or Layer> New .. > Layer via copy ..
Now with the new layer you just created, right-click on it and Blending Options … and completed with the following data.
It is really easy, first let Overlay Colors which is on the left panel and choose the color you want:

We now look lower, the latter option is Stroke and put the black, or another with the size you want, I have set 3.

Click OK and so is our photo, with its framework.

I hope you liked it!