This article is from the Viruses and the Mac FAQ, by David Harley D.Harley@icrf.icnet.uk with numerous contributions by others.
Sensei Consulting Macintosh WAIS Archives
"Inside the Apple Macintosh" - Peter Norton & Jim Heid (Brady) (The
2nd Edition is pre-PowerMac, and I haven't seen a later one, but
there's some surprisingly useful stuff in there).
"Inside Macintosh" (Addison Wesley). Essential reading for Mac
programmers. (Umpteen volumes of fairly low-level info. Expensive
(in the UK, at any rate), and whenever you get near some useful
info, it refers you to one of the volumes you haven't got. However,
the series has been re-vamped since I acquired my copies, and this
may be less than just. It's possible to download them in Acrobat
and in some cases other formats from:
where you can also order hardcopy and CD versions. Lots of other
"Power Macintosh Emergency Handbook" (Apple Computer)
MacFixIt "Troubleshooting for the Macintosh"
"Sad Macs, Bombs and other Disasters"
Ted Landau (Addison Wesley)
MacInTouch home page (info and services)
MacWEEK.com (Have run MacInTouch columns about the AutoStart worms.)
TidBITS (Have done many good articles on Mac/macro virus issues.)