How are your Linux skills these days? OS X is actually built on a UNIX-ish engine. Instead of making a travesty of an explanation, I'll just give you a link to Wikipedia's fairly cogent description of the
architecture of OS X and
Darwin, the open source, UNIX-like OS developed by Apple.
To get to the terminal, just open up the utilities folder, and the terminal application should be lurking therein. Its all Linux from there.
Tuxfiles.org is a good place for Linux Noobs to get their flippers wet. Just be careful with that 'rm' command, k?
--Oober Noober
P.S. There is no Terminal style application for pre X versions. Sorry if you're still using system 6.0.1.
