valve lapping...and heads

ok so i just finnished lapping the valves in the second set of heads for my 383, or so i think, im not one hundred percent sure what a finished valve seat and valve should look like, i tried to get rid of all the pitting in the exhaust valves and get them to look as smooth as possible, but could only do soo much.. as far as the intakes the same deal i tried to get them as smooth as possible but a couple have a fine groove or two, that i cant seem to lap out, is it a bigie?
is this easy to mess up?? and how much can it affect compresion (leaking ect)

thanks