2nd Pair versus an unknown

[HoldEmNewby]

I thought about checking flop, but that essentially turns my hand up. On the turn I am never sure how to play these.

Party Poker, $0.25/$0.50 NL Hold'em Cash Game, 5 Players
LegoPoker Hand History Converter

SB: $41.68
BB: $51.75
UTG: $21.81
Hero (CO): $50.12
BTN: $89.03

Pre-Flop: A[img]/images/graemlins/diamond.gif[/img] J[img]/images/graemlins/spade.gif[/img] dealt to Hero (CO)
UTG folds, <font color="red">Hero raises to $2</font>, BTN calls $2, 2 folds

Flop: ($4.75) 6[img]/images/graemlins/club.gif[/img] J[img]/images/graemlins/club.gif[/img] K[img]/images/graemlins/spade.gif[/img] (2 Players)
<font color="red">Hero bets $4</font>, BTN calls $4

Turn: ($12.75) 2[img]/images/graemlins/spade.gif[/img] (2 Players)
Hero ???

[traz]

I generally just cf against unknowns

[HoldEmNewby]

traz,

what read would you need to c/c? Is flop standard?