<<i'm doing this w/ the engine not running, however, nothing seems to
change when the engine is on.>>

Allow the engine to run, and after removing the engine cover see if the
clutch and compressor is spinning when the temp switch is turned all the
way to the coldest position.

If not, check for refrigerant in the system.
No freon , no compressor.
There's a low pressure switch to prevent it from self destructing.

<< when the "thermostat" switch is turned on (at all) it sounds like the
blowers or something start to operate in the overhead AC compartment
(definitely nothing under the engine hatch happens). but, like i said,
nothing happens when i use the "fan speed" switch. >>

Is the blower blowing or isn't it?
This paragraph is really confusing.
It isn't under the engine cover, but isn't the blower, and then it is.

There is a fuse strip under the the D pillar cover that carries all the
power to the AC system.
Check that out if neither the compressor or blower's are working.

<<� i've checked the two smaller fuses in the drivers-side pillar and
they're good. the "melt-away" fuse is also intact. i haven't check
anything further due to lack of a VOM meter.>>

You cab either use an ohm meter here to start checking for sources or
lack of power at all the connection's, but I prefer an "Ice Pick" type
12 volt power indicator tester.
It's faster, and it'll allow you to probe wires in the middle of a run
for power, and to stick connector's easier.

Less expensive too.

Start up front and check the two switches, and work your way back
testing for power at every connection and lead.

Get to the rear D pillar and check the power relays and fuses, high and
low pressure switches.

Make sure the system has penty of freon in it.