Laser Treatment for Small Scars on Upper Arms?

I have lots of scarring on my upper arms and I get lots of small spots. I admit that I pick them. I'm left with lots of small discolored scars, mainly brownish or light purple. I have fair skin. I'm considering having laser treatment done to approve the appearance, but I really want to know how effective it can be. Also, once you have had the treatment, how long does it take for the skin to heal and for the full result to be visible?