Going out on a limb here BUT... If they're actually serious about it I'd say Libranet 2.0, if they just want to check it out Mandrake or Redhat.
The reason I'm saying Libranet 2.0 only if they're serious is it'll cost them $50 to get it, unless they can bum a copy. IMHO it's well worth the money. You get the goodness of apt-get with a Debian woody based distro, without the install / configuration headaches that would drive a newbie straight back to WinDoze or worse