It depends how bad the scars are, but using a solution with salicylic acid in is good at getting rid of the pale bluey spot scars you get. It basically gets rid of the very top layer of skin. Loreal purezone do a clarifying lotion which is quite good.
For bad scaring this may not be enough though.
Bio Oil is supposed to be quite good, haven't used it myself though. In Argos they do a make up set thats supposed to cover scars, tattoos etc, its by rio and its what the NHS prescribe.
use bio oil, if you go in to your nearest boots or super drug store and ask for it they should know what your talking about.
or try a cream with vitamin E in
recently i was bitten by a dog on my face.. as soon possible i started applying vitamin e to it. they have it in a liquid or a stick, but the liquid is kind of gross feeling .. so i recommend the stick. i still have a scar but it's definitely fading.