AJ vs ???

[McNeese72]

I'm still learning and this is one of those type of hands that give me trouble. I haven't played but about 2 dozen hands with the villain and he seems pretty passive so far and hasn't raised pre-flop any. It's hard for me to read someone who is playing passively and doesn't raise.

PokerStars 0.25/0.50 Hold'em (10 handed) converter

Preflop: Hero is CO with A[img]/images/graemlins/heart.gif[/img], J[img]/images/graemlins/spade.gif[/img].
<font color="#666666">2 folds</font>, UTG+2 Villain/ calls, <font color="#666666">3 folds</font>, <font color="#CC3333">Hero raises</font>, <font color="#666666">2 folds</font>, BB calls, UTG+2 Villain) calls.

Flop: (6.40 SB) 2[img]/images/graemlins/club.gif[/img], T[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
BB checks, Villain checks, <font color="#CC3333">Hero bets</font>, BB folds, Villain calls.

Turn: (4.20 BB) 7[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Villain checks, Hero checks.

River: (4.20 BB) Q[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Villain checks, <font color="#CC3333">Hero bets</font>, Villain calls.

Okay, how should I have played this hand? I think I should have bet the turn instead of allowing the free card even though I don't think he is on a flush draw. But I think he still would call. On the river, if he would have bet out I probably would have folded, so I went head and bet after he checked hoping he wouldn't check raise. Should I go ahead and just check to the showdown?

It's hands like this that can cause me problems. When my opponent doesn't show any agression, is passive doing a lot of calling, and I don't have much of anything myself, I get lost between being aggressive or checking down with them.