This comment on the linux tutorials of bucky is worth a facepalm.
There will soon be a time where I get this. Now is not that tie.
OSX, and Linux are very similar. It is much closer to FreeBSD than Linux, but for the basics, and fundamentals, it will work fine. Knowing one well, easily transposes to the other.
So he is going to follow a linux tutorial, on a mac then he can better just learn how a mac works.