KQs with straight draw... when to let go?

[Dave G.]

Hi. First time poster and all that. [img]/images/graemlins/smile.gif[/img] I've been reading these forums for a while but am still quite new to poker, so my game leaves a lot to be desired...

Anyway, I was hoping for some comments on the following hand, mostly the turn and river play (but all comments are welcomed [img]/images/graemlins/smile.gif[/img]).

Party Poker 0.5/1 Hold'em (7 handed) converter

Preflop: Hero is BB with Q[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/heart.gif[/img].
UTG calls, MP1 calls, MP2 folds, CO folds, Button folds, SB completes, <font color="#CC3333">Hero raises</font>, UTG calls, MP1 calls, SB calls.

Flop: (8 SB) 4[img]/images/graemlins/heart.gif[/img], A[img]/images/graemlins/diamond.gif[/img], J[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">SB bets</font>, <font color="#CC3333">Hero raises</font>, UTG folds, MP1 calls, SB calls.

Turn: (7 BB) 4[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
SB checks, <font color="#CC3333">Hero bets</font>, MP1 calls, SB folds.

River: (9 BB) 2[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, MP1 calls.

Final Pot: 11 BB

At the turn, I'm thinking that I'm probably beaten, but I don't want to show that I haven't made my hand yet. Was the bet a good choice?

At the river I'm thinking he may have just been along for the ride (he never raises), so I bet thinking HE may fold on the blank river card. Good? Stupid?

Basically I have trouble letting go of hands at times, mostly because I don't know WHEN to let go. I appreciate any comments here. Go easy on me. [img]/images/graemlins/smile.gif[/img]