Can they download it on another computer and save it to a disk or something then set it up on the other computer without internet?
Yes you can. when you download, choose
Save rather than run. Then copy the installer file (either an iTunesSetup.exe or an iTunes64setup.exe) to your portable media and carry it to the other PC.
The primary issues on iTunes for Windows are making sure you get the 32-bit or the 64-bit installer. Usually the iTunes for Windows download page automatically detects which kind of operating system the downloading-computer has ... but if you're trying to download (say) a 64-bit iTunes64setup.exe installer file on a 32-bit PC, that can be a disadvantage.
Here's a link to a page with a direct download for a 64-bit iTunes64Setup.exe installer file (in case you need to get a 64-bit on a 32-bit PC):
http://support.apple.com/kb/DL925
To download a 32-bit on a 64-bit PC go to the standard page and get the option that
doesn't mention 64-bit (you'll know you've gotten the 32-bit one if the file is called iTunesSetup.exe).
http://www.apple.com/itunes/download/