1. after you added the background and the png(s) to get the outlines go to pen tool (P)
2. now, be sure you have selected shape, fill: no color and stroke: white (or the color you want the outline)
3. now just go with the pen tool where you want the outline, just like this:
OPTIONAL TIP: HOW TO GET GLOW
now, this is very simple.
on the window layers, down you'll see a "fx" button. click there.
now there'll be some layer styles, but you must go to the "outer glow" style
play with the setting until you like the final result. here are my settings that i used:
add your psds and what you have to add and this is it, you have an outline. simple like quantum physics, right? hahaha