Only if you promise not to listen or play any manson.... ...ok fine

Place your right hand lightly on the string that your palm muting near the bridge(the metal thing that holds the end of the strings on the guitars body).Its ok if your palm touches other strings that your not picking/playing

For a "loose" palm muting sound,rest your hand closer or even halfway on the bridge

For a "tight" palm mute(best with heavy distortions)rest your hand right above the bridge pickup and play.

It simply gives you that "chug" sound with distortion.

and for the love of music heres a list of metal bands you should check out...

Arch Enemy
Necrophagist
Children Of Bodom
In Flames(old stuff like whoracle,colony or jester race)
Death
Decapitated
Wintersun
Arsis
Immortal
Soilworks first album(steelbath suicide)
Krisiun(their latest stuff kills)
At The Gates
Dimension Zero
Martyr
Slayer(old stuff like reign in blood or south of heaven)
Symbyosis


That should get you started on some real metal.