whammi bar/tremolo

I got my guitar a while ago and never ended up screwing the whammybar/tremelo (don't know which one it is) on to the actual guitar. I know where it goes (the onli empty hole that it can screw into into the part where all the strings enter the head, i think its called the bridge) but i'm not sure how to do it. I hav tried just screwing it in but i don't really know how it works and what it's supposed to do exactly. How tight does it have to be and how does it work?

tremelo is the proper name but whammi is used as well so it doesnt really matter, tremelo is more to do with the type of bridge it is.
1)screw it in until it is on the last turn
2)hold the bar with a couple of fingers and play a note
3)gently push the bar toward the body of the guitar
this will make the bridge tilt against the body og the guitar changing the length of the strings and flattening the note being played, moving the bar in and out will make a tremelo effect and pushing the bar down is a whammy
hope that has helped
check out www.guitarshredshow.com and look in the lesons section i think it show a few whammy tricks

thanks tonnes for the help, will try it out soon! One more thing, does using the Trem bar too much put ure guitar out of tune easier?

yer on mine its horrible for detuning it, i used it loads when i got it n now i hate it bein off because it give that little extra thing when you cant think of anything else to do in fact im goin to go n put it n n play now
rock on dude