Flush on river - what to do?

[jfq4999]

I know posting in the cutoff isn't the best idea, but I'm still lost here. Should I have bet the turn when those flop calls kind of seemed like both of them were on flush draws too? And how do I play that river with a mediocre flush?

Party Poker No-Limit Hold'em, $ BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

MP ($80.09)
Hero ($50)
Button ($86.52)
SB ($49.50)
BB ($22.70)
UTG ($87.65)

Preflop: Hero is CO with 5[img]/images/graemlins/heart.gif[/img], J[img]/images/graemlins/heart.gif[/img]. Hero posts a blind of $0.50. SB posts a blind of $0.25.
<font color="#666666">1 fold</font>, MP calls $0.50, Hero (poster) checks, Button calls $0.50, <font color="#666666">1 fold</font>, BB checks.

Flop: ($2.25) 6[img]/images/graemlins/heart.gif[/img], 8[img]/images/graemlins/heart.gif[/img], 3[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
BB checks, MP checks, <font color="#CC3333">Hero bets $2</font>, Button folds, BB calls $2, MP calls $2.

Turn: ($8.25) T[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
BB checks, MP checks, Hero checks.

River: ($8.25) A[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">BB bets $3</font>, <font color="#CC3333">MP raises to $8</font>.