When I sing in a low quite voice, I think (personally!) that I can sing good. I can stay in tune with most songs.

But when I try and sing loud, I don't sound half as good. Is this normal? Can a singer just rely on his/her mic to boost their volume?

Also, anytips on singing in general. I'm going to try singing for my band, which I am very nervous about!
Not really^

Actually,, it is pretty hard to learn to sing loud and play (I'm assuming you play guitar/bass) at the same time, and singing in tune at a decent volume is something you need to learn to do, because if you just whisper into the mic, nobody can hear you because the mic will pick up alot more than just your whisper.
don't mean to scare you, but what you hear is not your real voice, you hear your own voice different than other people do. so you'll know what it sounds like when you sing miced up (or you can record yourself)...
Like what 666 said. But if you can sing in tune with the singer in the song you'll probably sound ok just different when you hear your voice recorded.
i can attest to that, I personally think I sing great, of course thats me hearing my voice, everythings in tune, and all the words are pronounced, etc.

i record myself, it sounds like a shy kid mumbling words, which i dont get, since i know i enunciate every word, because i'm a terrible mumbler, so when i sing i try not to, but apparently i still do, even when moving my mouth more than i ever have in my life