In mandriva, urpmi, and the core 'drake utlilites are installed by default.
Before you can use them to download and install packages however, you should use easy urpmi ( http://easyurpmi.zarb.org/
) to setup the database.
just pick the sites you want to use, copy the commands to your shell (as root), and wolla!
The 'drake utilities are a gui frontend for urpmi. The quickest way to launch the gui is the computer icon with the red badge/button/whatever on the taskbar. Click that, enter root password, click software, then choose install, update, or whatever.
Also at this point you can use urpmi to install packages. Go to a cli/command prompt, su root, then urpmi *pack-name*
to install. urpmi.update
to update, etc.
I'm guessing they will want to use the gui though (unless you're ssh-ing into the box).
NOTE: reference to "can't find urpmi": you have to su root before you can find urpmi, or anything else that requires root level access, it'll act like the file's not there.