You'll need the WIA driver if you want to connect the camera directly to the PC via the FireWire cable. You'll also need the EOS utility to download the images from the camera to the PC.
If you're just going to use the card reader, it'll depend on if you're shooting just jpegs, or RAW.
If you're shooting jpegs, you shouldn't need anything, just plug the memory card into the card reader, and that into the PC and copy the files to the PC and edit them in your favourite image editing application.
If you're shooting RAW, it'll depend on what applications you're using. If you use Photoshop CS2, ACR (Adobe Camera Raw) with the latest updates should be able to read the RAW files without issue. If you want to use the Canon software, you'll really only need DPP (Digital Photo Professional).
To play it safe, I'd recommend EOS Utility, ZoomBrowser EX and DPP. The software on Canon's website are all updaters, they require you to have a full version already installed on the PC, which means they're useless to you.
Whilst this isn't strictly legal from some people's points of view, my suggestion is to go here:
http://web.canon.jp/Imaging/sdl/dpp-e.html
Select the 1D model from the drop down menu and enter your camera's serial number. This will allow you to download a full version of DPP v1.0. It's old, but you should then be able to download the updater versions for ZoomBrowser EX, EOS Utility and DPP in order to get the latest & greatest versions 
An alternative is to buy a CD from Canon service, probably cost you around US $10 or so.
Hope this helps.
Dave