well first I'd work on getting that voice of yours to come out at atleast your speaking level, if you can only do it at a whisper.
Then you'd want to turn the volume up on the PA, put some reverb on there, and mess with the settings untill you're happy. Now, if you have more equipment, like a mixer, you could use some other stuff (mixer is usualy enough).
Why I said to turn up the volume is simple, not everyone can make their voice project while trying to growl like bodom or anything of that sort. If you notice, Alexi Laiho looks like he's barely trying when he sings... that's because he's using that volume knob and the mixer.
I can do bodom growls fairly well, and on some songs sound almost identical (when I want to, it's not my actual voice), and I do all of those things that I mentioned.
But if you're going to do any other type of singing, not like bodom, maybe cleaner, you'll need practice and learn how to breathe properly (also use your diafraghm, you should do this anyways).