don't expect to get gui as friendly as windows. This will never happen in linux. At least not in short term.

I suggest you just install one distro that is easy to use such as ubuntu or opensuse then let him try. If he doesn't like it then move back to windows.

IMHO, linux is still not mature enough to be used as desktop for common people. It still need a bit of technical aptitude to use linux as desktop. Those who are inept will definitely be stuck not knowing what to do.

As for 64bit vs 32bit, I would say go for 64bit. Linux's 64bit platform is already very stable. They were out way long before windows 64bit.