400NL - Need a little help with betsizing

[willw9]

Villain is littlerock09, relatively unknown, probably taggish and solid if I had to guess. I think he raised in the CO or button in both of the last 2 orbits and took the blinds both times. My image should be taggish as well.

Full Tilt Poker, $2/$4 NL Hold'em Cash Game, 5 Players
LegoPoker Hand History Converter

CO: $349.60
BTN: $502.90
Hero (SB): $438.40
BB: $608.55
UTG: $430.90

Pre-Flop: Q[img]/images/graemlins/spade.gif[/img] K[img]/images/graemlins/diamond.gif[/img] dealt to Hero (SB)
UTG folds, <font color="red">CO raises to $14</font>, BTN folds, <font color="red">Hero raises to $52</font>, BB folds, CO calls $38

Flop: ($108) T[img]/images/graemlins/club.gif[/img] 6[img]/images/graemlins/club.gif[/img] J[img]/images/graemlins/diamond.gif[/img] (2 Players)
<font color="red">Hero bets ?</font>

What's my bet here and why?