Originally Posted by Pokerstudent
We do NOT know if he is a good or bad player.
Yes we do. If he's open-limping every hand, he's very fishy. Still, he does have position on you, so it depends on what type of fish he is. If he's a calling station, raise with any pair, any suited connector, and ace, and king and most of the queens. After the flop it's pretty easy to play against this kind of players, just value bet him do death if you hit, or check it down if you don't. If he's weak, raise ATC and make a continuation bet no matter what comes, he'll be folding most of the times.
So, basically, just see how he plays after the flop and take advantage of him.