100NL Evaluating thin value bets: Value Bet this 2 pair on this river?

[onoble]

No real history, villain 31/10/2

PokerStars No-Limit Hold'em, $1.00 BB (9 handed) internettexasholdem.com

Button ($41.80)
SB ($107.25)
Hero ($60.50)
UTG ($94.40)
UTG+1 ($103.50)
MP1 ($17.10)
MP2 ($334.35)
MP3 ($81.65)
CO ($33.30)

Preflop: Hero is BB with 2[img]/images/graemlins/heart.gif[/img], A[img]/images/graemlins/club.gif[/img].
<font color="#666666">5 folds</font>, CO calls $1, <font color="#666666">1 fold</font>, SB completes, Hero checks.

Flop: ($3) A[img]/images/graemlins/spade.gif[/img], 6[img]/images/graemlins/heart.gif[/img], Q[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
SB checks, <font color="#CC3333">Hero bets $2</font>, CO calls $2, SB calls $2.

Turn: ($9) 2[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
SB checks, <font color="#CC3333">Hero bets $6</font>, CO folds, SB calls $6.

River: ($21) 9[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
SB checks,

If I bet here... how much and what do you do if c/r?

Thanks