The above frame has been converted from Raw using the standard nonLinear conversion (as you use for your daylight photos), Daylight White Balance (I actually used Custom White Balance since I was using a modded 20D, but DWB on an unmodified 20D should give a very similar result) and then I simply stretched the brightness histogram, resized down and sharpened it. About as simple post processing as it gets.

Things to notice:

Distended stars at the edges and magenta rings around the brightest stars are due to the aperture used being too wide open for this lens. As you close down the aperture the lens behaves better. Wide angle lenses are particularly prone to these defects. Hence my suggestion that you should start off with f2.8. For serious astrophotography this particular lens has to be closed down to f5.6 or f8, but f2.8 is adequate for most primes (non-zooms) if the final product is for web presentation (1000 pixels across) or A5 prints. Some lenses may even produce satisfactory A4 prints. Canon primes from 100mm upwards are often usable wide open to yield satisfactory A4 prints.

The exposure length used here was 10sec. It is short enough that there is almost no star-trailing visible, even when viewed at 1:1. But you always want to use the longest exposures possible to get good Signal to Noise, especially when pointing away from the brightest patch of sky, as in the above photo. Hence my advice to use the exposures listed on the previous page, but not longer. The trails will be longer, but the stars should look round enough after downsizing for web use, i.e. downsizing to between 800 and 1000 pixels wide. You will particularly appreciate the longer exposures with longer lenses. It's always a compromise.