why ubuntu only? have a look at opensuse - personal favorite (but I run ubuntu,don't know why), mandriva. all of these are the most user friendly distros.
when I switch to linux... had no trouble at all, a part from finding simple IM client... I have pedgin and others, which are too way heavy :D
helping others at evgenyk.nz
Ubuntu is very good for customizing your GUI.
Take a look at http://www.gnome-look.org/ for themes and icon sets
Also look into compiz fusion which is basically the Linux alternative to Vista Aero