I just called on the flop because I had a good drawing hand, and potentially the best hand if he had AK, AQ. When I led out on the turn I was trying to represent a 7, and was kind of surprised that he raised - at this point I put him on a big pair. I fill up on the river, and check to him - it happened so fast that I wasn't really thinking about if I should value bet, but should I have? Would he have called?

PokerStars No-Limit Hold'em, $0.25 BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

SB ($16.65)
Hero ($34.15)
UTG ($6.05)
UTG+1 ($11.15)
MP1 ($12)
MP2 ($14.35)
MP3 ($26.50)
CO ($25.85)
Button ($31.70)

Preflop: Hero is BB with 5, 5.
6 folds, Button raises to $1, 1 fold, Hero calls $0.75.

Flop: ($2.10) 4, 7, 6 (2 players)
Hero checks, Button bets $1.5, Hero calls $1.50.

Turn: ($5.10) 7 (2 players)
Hero bets $2.25, Button raises to $4.5, Hero calls $2.25.

River: ($14.10) 5 (2 players)
Hero checks, Button checks.

Final Pot: $14.10

Edit: Now that I'm thinking about it, this question is pretty retarded, of course I should have led out. Meh, I'll see what you guys have to say.

only reason not to bet out is if he's the type of player who was likely to be bluffing/semibluffing on that turn card. If so, he's either going to bet with air on the river or else have completed his semibluff on the river. The min-reraise with position probably isn't a turn bluff, though, so the only way he's betting this river for value is if he has a bigger boat. Yeah, bet out between 10 and 15 dollars, if he reraises all-in, first puke, then call.

The only way you can NOT lead out here is if you're SURE he's going to bet the river if checked to.
This is of course an indirect way of saying, lead out. Your hand is not only disguised, but you could potentially overbet it and get him to call with any hand that beats a pair of fives, imo.

Yeah, I think you have to lead out here. He may be willing to call a bet with a big overpair or a 7, but might lock up with those hands because the board is now 4567.