AK Sooooooted, River play...?

[Vavavoom]

PokerStars No-Limit Hold'em, $2 BB (9 handed) FTR converter on zerodivide.cx

UTG ($292.15)
UTG+1 ($108.50)
MP1 ($54.45)
MP2 ($110.60)
MP3 ($112.70)
CO ($72.95)
Button ($126.25)
Hero ($115.15)
BB ($194)

Preflop: Hero is SB with A[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/spade.gif[/img].
UTG calls $2, <font color="#666666">3 folds</font>, MP3 calls $2, <font color="#666666">1 fold</font>, <font color="#CC3333">Button raises to $6</font>, Hero calls $5, <font color="#666666">1 fold</font>, UTG calls $4, MP3 calls $4.

Flop: ($26) 2[img]/images/graemlins/spade.gif[/img], 7[img]/images/graemlins/spade.gif[/img], 5[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
Hero checks, <font color="#CC3333">UTG bets $2</font>, MP3 folds, <font color="#CC3333">Button raises to $8</font>, Hero calls $8, UTG calls $6.

Turn: ($50) A[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets $20</font>, UTG calls $20, Button folds.

Was my turn bet donkish, should I have check-raised...?

River: ($90) 9[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>

I'm first to act ??? Whats my play.....