Pocket Pairs (KK) - I'm Totally Clueless

It's time I got started studying my play and the game in general a lot more, so here's what I intend to be the first of many poorly played hands!

BB was IRO 20/5/1.5
UTG was IRO 40/11/0.7
UTG+1 had only just sat down and was unknown.

IMHO, I turn super weak when an overcard to my pocket pair appears.

On the flop, my raise was intended to fold out a weak ace form BB + UTG.

Turn, as expected, it was checked to me - what's my line here against an unknown?

River, checked to me again (!). I am happy with my decision to bet here.

Party Poker 0.50/1 Hold'em (10 handed) FTR converter on zerodivide.cx

Preflop: Hero is MP3 with K[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/diamond.gif[/img].
UTG calls, UTG+1 calls, <font color="#666666">3 folds</font>, <font color="#CC3333">Hero raises</font>, <font color="#666666">3 folds</font>, BB calls, UTG calls, UTG+1 calls.

Flop: (8.50 SB) 2[img]/images/graemlins/diamond.gif[/img], A[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(4 players)</font>
BB checks, UTG checks, <font color="#CC3333">UTG+1 bets</font>, <font color="#CC3333">Hero raises</font>, BB folds, UTG folds, UTG+1 calls.

Turn: (6.25 BB) 7[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
UTG+1 checks, Hero checks.

River: (6.25 BB) 3[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
UTG+1 checks, <font color="#CC3333">Hero bets</font>, UTG+1 calls.

Final Pot: 8.25 BB