I need some help/advice on a few hands here. All of them I found myself not knowing what to do or second guessing my judgement.

Hand 1 - UTG is a tight-ish player from what I've seen. I've only been on the table for around 15 hands.

Full Tilt No-Limit Hold'em, $0.10 BB (6 handed) - Full-Tilt Converter Tool from FlopTurnRiver.com

saw flop

MP ($6.20)
Hero (CO) ($5.65)
Button ($1.45)
SB ($11)
BB ($5.25)
UTG ($5.30)

Preflop: Hero is CO with K, A
UTG raises to $0.35, 1 fold, Hero calls $0.35, 1 fold, SB calls $0.30, 1 fold

Flop: ($1.15) 10, 9, A (3 players)
SB bets $0.50, UTG raises to $1, Hero folds, SB calls $0.50
__________________________________________________ ____

Hand 2 - Villain is an aggressive player. I min. betted flop due to a mis-click. Did Villain sense weakness from that and raise? And could I possibly have called on the turn?

Full Tilt No-Limit Hold'em, $0.10 BB (6 handed) - Full-Tilt Converter Tool from FlopTurnRiver.com

saw flop

CO ($7.20)
Button ($16.40)
SB ($1.75)
Hero (BB) ($24.95)
UTG ($18.25)
MP ($10.10)

Preflop: Hero is BB with A, Q
1 fold, MP calls $0.10, 3 folds, Hero raises to $0.30, MP calls $0.20

Flop: ($0.65) 7, 5, A (2 players)
Hero bets $0.10, MP raises to $0.95, Hero calls $0.85

Turn: ($2.55) 5 (2 players)
Hero bets $1.10, MP raises to $5.85, Hero folds

Total pot: $4.75 | Rake: $0.45
Main pot: $4.75 returned to MP
__________________________________________________ ____

Hand 3 - Villain likes to play a lot of hands. Couldn't put him on a hand but I figured I was beat here.

Full Tilt No-Limit Hold'em, $0.10 BB (5 handed) - Full-Tilt Converter Tool from FlopTurnRiver.com

saw flop | saw showdown

MP ($4)
CO ($7.10)
SB ($9.25)
BB ($7)
Hero (UTG) ($9)

Preflop: Hero is UTG with J, J
Hero raises to $0.35, 1 fold, CO calls $0.35, SB calls $0.30, 1 fold

Flop: ($1.15) 8, 10, K (3 players)
SB checks, Hero bets $0.70, 1 fold, SB calls $0.70

Turn: ($2.55) A (2 players)
SB checks, Hero bets $1.10, SB calls $1.10

River: ($4.75) K (2 players)
SB bets $3, Hero folds

Total pot: $4.75 | Rake: $0.45
Main pot: $4.75 returned to SB