Newbie with a flopped set

[Saborion]

Party Poker No-Limit Hold'em, $ BB (6 max, 6 handed) converter

Trying to learn the basics of NL. This hand came up shortly into my session and I'm looking for opinions about my flop raise.

Both the SB and MP are loose preflop. As usual? the MP isn't calling the flop bet without having some kind of hand. What "some kind" is I can only speculate about, maybe you can provide some educated guesses?

I raised the flop to sort of conceal the strength of my hand since I assume that most? players wait until the turn to raise their sets on non-scary boards like this. Am I wrong to think so? Anyway, if the SB, and hopefully the MP, do call my flop raise he/they will be pretty committed to the pot on the turn as well. Or?

saw flop|<font color="#C00000">saw showdown</font>

CO ($48.25)
<font color="#C00000">Hero ($75.95)</font>
<font color="#C00000">SB ($91.9)</font>
BB ($45.5)
UTG ($169.36)
MP ($48.1)

Preflop: Hero is Button with 5[img]/images/graemlins/club.gif[/img], 5[img]/images/graemlins/spade.gif[/img]. SB posts a blind of $0.25.
UTG calls $0.50, MP calls $0.50, <font color="#666666">1 fold</font>, Hero calls $0.50, <font color="#CC3333">SB (poster) raises to $2.75</font>, BB calls $2.50, UTG folds, MP calls $2.50, Hero calls $2.50.

Flop: ($12.50) J[img]/images/graemlins/spade.gif[/img], 4[img]/images/graemlins/club.gif[/img], 5[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">SB bets $10</font>, BB folds, MP calls $10, <font color="#CC3333">Hero raises to $30</font>