Thoroughly confusing ATs hand

[Wepeel]

Party Poker 3/6 Hold'em (9 handed) converter

Preflop: Hero is BB with T[img]/images/graemlins/heart.gif[/img], A[img]/images/graemlins/heart.gif[/img]. MP2 posts a blind of $3. MP3 posts a blind of $3. CO posts a blind of $3.
UTG calls, <font color="#666666">1 fold</font>, MP1 calls, MP2 (poster) checks, MP3 (poster) checks, CO (poster) checks, Button calls, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises</font>, UTG calls, MP1 calls, MP2 calls, MP3 calls, CO folds, Button calls.

Flop: (13.33 SB) A[img]/images/graemlins/club.gif[/img], T[img]/images/graemlins/club.gif[/img], 7[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(6 players)</font>
<font color="#CC3333">Hero bets</font>, UTG folds, <font color="#CC3333">MP1 raises</font>, MP2 calls, <font color="#CC3333">MP3 3-bets</font>, Button folds, Hero calls, MP1 calls, MP2 calls.

Turn: (12.66 BB) 6[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
Hero checks, <font color="#CC3333">MP1 bets</font>, MP2 folds, <font color="#CC3333">MP3 raises</font>, Hero calls, MP1 calls.

River: (18.66 BB) 5[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, MP1 checks, <font color="#CC3333">MP3 bets</font>, Hero calls, MP1 calls.

Final Pot: 21.66 BB

Wow this hand just had me scratching my head the whole way. OK, I know I usually tell people you need reads to make the whole hand analysis more beneficial, but by the preflop action (3 posters!!!) you should realize I just sat down at the table intending for it to fill up, so unfortunately I do not have any reads.

OK, I started to analyze my play in this hand, but I think it might be better if the other posters analyzed this hand and tell me the good and bad of it before I delve into any logic I had for this hand.