in terms of general advice...
hmmm...
I always shoot in raw, disk space is cheap enough these days that there is no real reason not to.
Once I have copied all the images to my file server I convert all the photos with no adjustments at all to .jpg files no larger than 1000 pixels in height or width. This lets me go through them quickly and prune the ones I don't like.
oooh... here's one... Always leave the images on the memory card, formatting them just before the next shoot, if you have a short term disaster it's good to know you still have them on the card.
Generally though i'm not too sure there any sure fire things to do or avoid. RAW files make changing things like the white balance nice and easy if you're a bit off.
All the advice above is great but one thing I would really recommend is to get your hands on Adobe Lightroom or Aperture (for mac) - i use lightroom and love it - really simplifies my worklow and lets me apply fixes and tweaks ver7y easily. plus it doesnt scare me like photoshop does - plus at the end of the day photoshop was not designed for this anyways.
The full product is called Adobe Photoshop Lightroom and is a stand alone program - its on V2 now so you can pick up V1 for £70 or so. It's not the only tool out there and if your willing to look after your own workflow then the GIMP (think free photoshop) is free and a great image editing tool.
Lightroom is a lot more expensive than free but imho is the best ive used. Im sure they used to do a trial of it. - check here
Tom