Betting and Pott Odds for Hold Em

[JSHamm]

This is just an example but I'm wondering how you would handle this situation

Say you are dealt K [img]/images/graemlins/diamond.gif[/img]K [img]/images/graemlins/heart.gif[/img]

and your opponent is dealt A [img]/images/graemlins/spade.gif[/img]J [img]/images/graemlins/spade.gif[/img]

the flop comes down as 3 [img]/images/graemlins/spade.gif[/img] K [img]/images/graemlins/club.gif[/img] 8 [img]/images/graemlins/spade.gif[/img]

Now you put the opponent on a flush draw so how do you handle betting going into the turn?
He has 3.25:1 odds on making the flush so do you bet higher than the odds trying to scare him off? If so, isn't his call justified by the pot odds? Or do you bet less the the odds given thereby giving him unjustified reason to call?
I'm new to poker, about two months, so I was wondering how this situation should be handled best.
BTW, this is my first post so hello to everyone.