AJ ui: Turnbet?

[Scipio]

There are no draws on the flop.
-> villian made a bluffcall or had a madehand.
If i always bet the turn i think my strategy is exploitable.
So how often should i bet the turn and how often should i play c/f?
What change if villian is a good TAG?

Villian Semi-LAG

Party Poker 30.00/60.00 Hold'em <font color="#0000FF">(5 handed)</font> link

Preflop: Hero is SB with J[img]/images/graemlins/heart.gif[/img], A[img]/images/graemlins/club.gif[/img].
<font color="#CC3333">UTG raises</font>, <font color="#666666">1 folds</font>, <font color="#CC3333">Hero 3-bets</font>, <font color="#666666">1 folds</font>, UTG calls.

Flop: (7.00 SB) 3[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/spade.gif[/img], 6[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, UTG calls.

Turn: (4.50 BB) 4[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
Hero ?