I'm slightly confused. Lets get this straight.

You are shooting your short, sound and all in one shot. Then you are going to go back when you edit and cut out the sound, then put it back in
or is it
You are shooting the short, cutting out the sound, then rerecording the sound.
Or
You are shooting the short and don't like sound so you're cutting it out.
or
You need sound, so you are recording it onto your camera then deleting the picture and just using the sound?

Get a bit more specific please.

And what do you use to edit?

You people have held me back long enough, I'm going to clown college!

ok how do i explain this..all the sounds that go into a movie, like specific sounds like a door closing, or some chewing or swallowing, can i record these sounds into my camera and in post seperate these sounds from the picture and add them to any part of the film??

Are you talking about doing Foley sound? Because if you're doing that you could just shoot everything, edit the footage together and then decide what kind of sound you need, where it should go and how long it should be and then go back with your camcorder and capture all the specific sounds you need from the enviroments you shoot in and then edit them into your film. This can be difficult and time consuming.

Have you tried looking for low cost mics on ebay? Using a seperate mic hooked into your camcorder will give you better sound than using the mic built into your camera because those mics tend to pick up the sound coming from the inner workings of the camera which can get annoying. If you decide to do the Foley option just make sure to get ALL the sound you need and take the time during editing to make it work. Look at everything in the shot and the scene as a whole and take note of what should be making noise. Oh and always have a room tone track to disguise your sound edits.

Hey i DID learn something in college! How 'bout that!