> There are books describing it, but personally I don't have the moolah.
> And what if the book is too technical that I can't understand the answer
> or that it doesn't even contain the answer? I'm stuck with a book that
> I've wasted money on and I don't have the material I want.

If you live near a decent-sized university, you might be able to
use their library facilities.  I know that the state university
here will issue library cards if you have a valid state driver's
license, and they'll let just about anyone in to browse.  They also
don't get snippy if you want to read the book there (Barnes & Noble
sometimes does ;-).  Also, libraries are more likely to have older
books.  The best ones for getting started are, of course, the Design
and Implementation of the 4.4 (or 4.3) BSD [UNIX] Operating System.
The 4.3 version has a lot of good information, and the 4.4 version
is a more relevant to NetBSD.  The 4.4 version took "UNIX" out of
the title.

m68k documentation can be found in pdf format on the web (at
motorola's site: http://www.mot.com/SPS/HPESD/prod/index.html).
Some Apple documentation is available on-line, but I'm not sure
how much (I haven't poked around their site for a while).

You're also welcome to read code and manual pages and ask
questions.  ;-)

-allen