What software do you use? Certain software doesn't allow you to apply frames/borders.
I use this free software called PHOTOSCAPE and it works wonders for a noob 
Clicky Once installed click on editor, open the picture you want, edit 'till your hearts content and then underneath your photo there will be a box titled NO FRAME if you click on it there are about 50 frames to choose from.
Hope this helps.

There's a couple of ways to do it in CS3 (I'm guessing PS 7 should be able to do these but I'm not sure - you may need to hunt around the drop down menus a bit).

Ctrl A --->  Edit ---> Stroke ---> Select your colour, pixel width, check the 'centre' location check box, blending mode normal, opacity 100% - this method will crop your images by the pixel width that you enter.

Bit more complicated method that won't crop images:

Layer ---> New Fill Layer ---> Solid Colour ---> No need to re-name the layer (unless you feel the need), colour=none, mode=normal, opacity=100% ---> OK ---> Choose your colour ---> OK (image should change to colour you chose)

Double click your original layer in the palette (should be named 'background') and rename it (otherwise you can't move it)---> drag original layer above your colour fill layer (image should re-appear) ---> Edit ---> Transform ---> Scale ---> Then either manipulate the image with the tool or go up to the 'W:' and 'H:' boxes at the top and enter 98, or there abouts, to resize your top layer.

Layer ---> Flatten Image ---> Save as


Hope that works for you!

I love how complicated most people make things in photoshop.


Image---> Canvas Size----> adjust the canvas size appropriatly and change the little colour box at the bottom to whatever colour you want.