KK when villain bets pot on flop

[llamage]

Villian is like 60/25..so his range could be anything ...but I knew he respected my play so maybe he thought i missed the flop and tried to take the pot away from me with an overpair? It might be a set...but at these limits they always slowplay a set. So I was REALLY confused by this bet... Anyways I raised ... and if he pushed I would've folded. People tell me I shouldnt "raise for information"(just call to see a showdown). I should only raise if I believe I have the best hand...but i was half unsure/ half believed that i had a great hand so is this worth a raise on the flop? Ya...really dumbfounded by this.

PokerStars No-Limit Hold'em, $0.10 BB (5 handed) Hand History Converter Tool (http://poker-tools.flopturnriver.com/Hand-Converter.php) from FlopTurnRiver.com (http://www.flopturnriver.com) (Format: 2+2 Forums)

MP ($22.65)
Button ($3.20)
SB ($7.50)
BB ($12.15)
Hero ($16.70)

Preflop: Hero is UTG with K/images/graemlins/heart.gif, K/images/graemlins/diamond.gif.
<font color="#CC3333">Hero raises to $0.4</font>, <font color="#666666">1 fold</font>, Button calls $0.40, <font color="#666666">1 fold</font>, BB calls $0.30.

Flop: ($1.25) 7/images/graemlins/spade.gif, 4/images/graemlins/heart.gif, 9/images/graemlins/diamond.gif <font color="#0000FF">(3 players)</font>
<font color="#CC3333">BB bets $1</font>, <font color="#CC3333">Hero raises to $2.5</font>, Button folds, BB calls $1.50.

Turn: ($6.25) 9/images/graemlins/heart.gif <font color="#0000FF">(2 players)</font>
<font color="#CC3333">BB bets $1</font>, Hero calls $1.

River: ($8.25) 2/images/graemlins/heart.gif <font color="#0000FF">(2 players)</font>
BB checks, Hero checks.

Final Pot: $8.25

[rakes.a.beach]

If yo uwant you can bet 5 on the river. But a check is fine also.

[Genz]

You shouldn't raise for information alone, because the info you get is very inaccurate and not worth the price. Getting information is often a nice side effect of a bet that you made for a number of reasons like value and protection.

I have no idea why you think that villain respects your play. In my experience, players with these stats don't respect anything, not even their own bankroll.
I would have called a push without any hesitation here on this limit. I raise to 3.5 on the flop (for value and a little for protection against weird draws). His turn bet looks very weak. It's either a block or he want's you to raise. Nevertheless, I don't like the top board card pairing, so I think it's ok to call. I don't care to protect myself against a runner runner flush or a gutshot too much at this point since I don't want to face a push on the paired board.
River check by villain is weird and pronounces the idea that he was blocking or bluffing a 9 on the turn. I'd mostly value bet here unless I know that villain trys to win an award in trickiness and would raise here (unlikely).