The FSM for my '01 lists test conditions as 1500rpm; blower on hi; A/C on; Temp control at full Cool position; doors of truck open.

Not sure whether your 96 has a sight glass (on top of the receiver-drier -- usually near the condenser up front), but if it does, you use it to judge the amount of referigerant in the system:

Bubbles present in sight glass -- low referigerant (a few bubbles okay at high ambient temps if cooling is okay)

No bubbles -- no referigerant, just right, or too much:
1) if no difference in temp on compressor inlet and outlet -- empty or nearly empty
2) noticeable difference in compressor inlet/outlet temp -- correct or too much

3) Sight glass stays clear immediately after turning A/C off -- too much

4) Sight glass foams then stays clear after turning A/C off -- correct

FSM lists "normal" pressures as 0.15 - 0.25 MPa (1.5 - 2/5 Kgf/cm2) on the low side, and 1.37 - 1.57 MPa (14 - 16 Kgf/cm2) on the high side (noting that guage indications may vary slightly due to ambient temperature conditions).

I don't have the conversion from the above values to psi, but will look around and re-post if I find them.

Edit: That's 21-36 PSI Low, and 198-228 PSI High

See also: Online Pressure Conversions