I reciently got a clarinet and the keys are really dirty. Is there any way to clean them with out damaging them?

It depends on the material. Silver and nickel need to be treated differently. It really doesn't affect how the instrument plays, but if you still want to clean the keys, I recommend taking the instrument to a qualified repair person, who can either do the cleaning, or at least provide you with good information.

Just tarnished. My band teacher thinks that it was in a fire and that the keys just have soot on them

that sounds... sketchy. and unlikely? i can't imagine a fire would damage the keys and not the rest of the horn.
some of my keys are so dark they look almost burnt, too. one of them (low Eb) the silver plating has worn off altogether to a copper color underneath. (which is weird because it's not like you use low Eb so often that it would rub off. i don't know.)

it gives it character.

Haha, the stranger the better =D

it's hard to know without a picture, and even then, it's hard to know because it's all grungy.

But if you don't want a tech to look at it you have two options.
[1] Try silver cleaner on it - if that doesn't clean it fairy quickly,
[2] then a regular cleaning cloth with a rouge cloth in it would definitely clean it (or a metal polish like MAAS polishing creme). I would use the silver stuff first because a rouge based cloth would scratch silver.

the maas polishing creme will get the heavy gunk off but won't polish it all up brilliantly. that requires a lighter polishing agent.

thanks i got maas and it cleaned the keys. and ase you said... the keys arent very shiny but there alot cleaner