Help with my cannon rebel?

I have my camera set to manual and for some reason it won't let me change the aperture anymore? It's just stuck on 00 it allows me to change the shutter speed but not the aperture and I can't figure out why! Please help, photo project due soon!

1st make sure your lens' aperture ring is in the auto position.

Can you adjust it if the camera is set to Aperture Priority?
Have you used Manual before?and it now doesn't work
You're holding down the AV+/- button when you turn the wheel?Is the lens on correctly?just asking

try reseting the camera, i think SLR's have a reset switch which restores to factory defaults.
it sounds like u have a bad connection on the BUS, probably a stooped link
try messign with the buttons ,press on it hard and stuff like that. I experienced the same thing and after a few presses it functioned again.

What EOS model do you own. Turn the power off, remove your battery then your lens and turn you mode dial to you Full Auto position. Now replace the lens, battery and now turn it back on, try a few different modes like TV & AV to see if it will allow you to change the settings. Do this before you try full manual. If all goes well then your next step would be the manual mode, if the problem persists you should take into you local Canon dealer for them to take a look at it. My question to you is was at some point you Camera may have been dropped.