[Cheshire]

This is my first post so if I posted incorrectly let me know.

Texas Hold'em Limit ($0.25/$0.50)
dealt to Me J [img]/images/graemlins/spade.gif[/img] T [img]/images/graemlins/club.gif[/img]]
UTG: folds, UTG+1: calls $0.25, UTG+2: calls $0.25
Me: calls $0.25, MP2: folds, MP3: raises $0.50, CO: folds
Button: folds, Small Blind: calls $0.35,
Big Blind: calls $0.25, UTG: calls $0.25, UTG+1: calls $0.25
Me: calls $0.25
----- FLOP ----- (12 Small Bets)
[4 [img]/images/graemlins/heart.gif[/img] 7 [img]/images/graemlins/spade.gif[/img] 8 [img]/images/graemlins/heart.gif[/img]]
All check to MP3, MP3: bets $0.25, Small Blind: calls $0.25
Big Blind: folds, UTG: calls $0.25, UTG+1: calls $0.25
Me: calls $0.25
----- TURN ----- (8.5 Big Bets)
[3 [img]/images/graemlins/diamond.gif[/img]]
All check to MP3, MP3: bets $0.50, Small Blind: calls $0.50
UTG: folds, UTG+1: calls $0.50, Me: calls $0.50
----- RIVER -----(12.5 Big Bets)
[4 [img]/images/graemlins/spade.gif[/img]]
Checked to me, Me: bets $0.50, MP3: calls $0.50
SB: folds, UTG+1: folds
----- SHOW DOWN -----
Me: shows [Js Tc] (A Pair of Fours, Jack high)
MP3: shows [Ac As] (Two Pairs, Aces and Fours, Eight high)
MP3 collected $6.90 from Main pot

It might have been a loose preflop call from MP1, but
after that I figgure I have to call. On the flop and turn I figgured that if there was a chance MP3 had unpaired high cards then I had the odds to continue. And on the river I wanted to at least try to win the pot. Might a check raise on the river have been better or just give it up?
This hand left me feeling like I know nothing about poker.
How can I play it better?