Hi Dave,
I've used my little Canon S3IS for photographing the night sky.
You won't be able to get a good picture from a single photo, you will have to take multiple images and stack them. It's not hard to do, and it's good practice for when you get your hands on a "real" camera.
The basic recipe for a good wide field photo
1. set focus to infinity
2. ISO 400 is better than ISO 800 which is too noisy, but experiment with ISO 800, if you take enough photos, stacking will reduce the noise.
3. take as long an exposure as you can. 15 seconds is fine
4. use auto white balance
5. take as many photos as you can, at least 20
6. after you've taken your photos, put the lens cap on and take the same number of photos with the lens cap on. These are your dark frames.
7. Don't use any Zoom at this stage.
8. If you can, set the camera for a 2 second timer so you don't get any camera shake when you press the shutter button.
Processing
1. Download a copy of Deep Sky Stacker, it's a free program.
http://www.deepskystacker.com/
2. Download the photo's from the camera. Sorting them into 2 files, one for Dark Frames, one for Picture files.
3. Open Deep Sky Stacker
4. Click on "Open Picture Files" and choose your picture files.
5. Click on "Open Dark Files" and choose your dark files.
6. Click on "Check All"
7. Click on "Stack Checked Pictures"
8. Wait for the computer to do it's thing.
9. You can use the sliders under the final picture to adjust it to your liking. This is the fun bit.
10. Click on "Save Picture to File" make sure you tick the box that asks if you want to save any adjustments you've made, other wise you'll lose it.
11. Open up your saved picture in the image processing program of your choice, PhotoShop, PaintShop, what ever and continue with your processing if you want to.
The only other advise I can add it that when you start to use the zoom on the camera, you will have to take shorter exposures, otherwise your star will start to trail. I've taken up to 74 images at 8 seconds each, to get a not too bad close up of the Eta Carina nebula.
It involves a lot of trial and error, but it's the only way to learn.
Good luck, and don't forget to post your images.