Hey Alcafuz,
I just finished writing code for using an electret with an Arduino. I posted my code in the topic about music detection. I use a 386 to amplify the signal first and it is just enough, more amplification would be better but would also be more expensive, so I made the code do the work. Let me know if you have any questions about it. Also when I was looking up specs on electret microphones most suggested low voltages around 2V so I used the 3.3V power with a resistor to power it, I don't know what my specific model mine is, it just came with a box of random electronics, but it seems to work well.