Here's what I can think of, some from what I always do, some from what I wish I had done:
Set the auto power down to 30 minutes - that way the camera will never power down, unless you forget to turn it off when you put the camera in the bag. When you take the camera out of the bag turn it on and put the strap around your neck. Whenever my camera is out of its bag it is ready to shoot. (I always do this)
As soon as you have the camera on and ready to shoot, if you don't need to shoot right away, spend a few seconds looking at all settings. Check mode dial, I usually set it to P or Av or Tv or M and usually want it on the right one for what I am doing. Chech drive mode, ISO, Focus mode etc. (This is good advice and one day I plan to use it!)
If shooting from a tripod without a remote release set mirror lockup and self timer for the 2 second delayed shooting. More importantly - when you are finished and take the camera off the tripod, set the mirror lockup back to disabled and drive back to 0ne-shot or continuous, BEFORE putting the camera away. (this will save you anxiously worrying about why the camera wont shoot a couple of days later, not that I have ever done that of course!).
When you get home transfer all images from all cards to your PC and format the cards. Charge all batteries. Put a card and a battery back into the camera and put the camera back in its bag. Put all other cards and batteries back into the camera bag. If you grab your camera bag and go shooting its good if everything you need is actually in the bag and ready to use. (I always do this and it does make life easy)
2 Batteries is the minimum requirement. (I have 2 Canons and there are 2 Power-2000 ones on order)
2 CF cards is the minimum requirement. (I have 2 512s)
If you don't own a wide enough lens for the landscape you are looking at, set the mode to M and set your aperture and shutter speed and take a series of shots panning and make sure there is some overlap between each shot. You can stitch together a panorama later. (I want a 70-200IS first then after that I'll consider getting a 17-40L)
If you drive to places to shoot, consider a charger that can use 12V, it couldn't hurt to put that in the car (I have 2 on order). If you have 2 fully charged batteries you probably wont need to recharge, but Murphy's law can be a **** sometimes.
RAM is cheap, your computer should have at least 512MB if running WinXP, I find 1GB RAM is nice. Remember that photoshop will open the 2048 x 3072 JPGs into an 18MB file (worse if RAW -> 16bit) per picture. (sometimes I have quite a few pictures open in photoshop at the same time)
Backup those image files! HDDs can crash! (if the files are too big and you don't own a DVD-Writer or anything else suitable, I'm sure your files will be fine, HDDs never fail for people that have important files that they haven't backed up, it just couldn't happen, could it?)
That's all I can think of right now, I hope some of it is helpful to some of you.