well.. my first suggestion is (if you yet miss this studyes) to start approaching max/msp using it to study classic sound theory and basic synthesis.
As a matter of fact max/msp is a wonderfull tool to learn how sound works.

Regarding OSX and macs, there is nothing to learn.. if you had some experience with windows machines, OSX will just works, looks and behaves better, faster and without pains.
There's nothing to learn.. unless you want to enter the world of UNIX.. of course.

what exactly do you want to do with Max?

my suggestions...

-join the max-msp list that is on the cycling 74 website... as it is the crux of the community...

-before you ask questions on the list... check through the documentation and tutorials... as most newbie questions are well answered within. also look at the help that comes with each object...

-a book that I've found helpful is the computer music tutorial by curtis roads. it touches on a huge variety of topics... is easy to read... and gets technical enough to get you started... good reading for the toilet!

as far as OSX... make sure that in your system preferences>energy saver settings you have the processor performance set to "high" for the "power adapter" configuration... otherwise... the default "automatic" will try to conserve energy by slowing down the processor... which can produce bizarro timing issues... as well as audio clicks.

also... I prefer the Max "overdrive" setting to be set to on... as it puts the midi events at a higher priority than the audio... giving you more accurate timing. If you don't have overdrive on... events like file opening and mouse clicks may temporarily pause your midi processing...

hope this stuff helps!