What are the next steps to troubleshoot a/c problem?

Hi.  We have a 1996 Toyota Tacoma Double Cab TRD Sport 4WD Pick Up Truck.  When we turn the A/C on on idle, we are not getting any cool air, but the electronic clutch works and engine loads down.  The belts are fine.  The filter behind the glove compartment is fine, and I vacuumed out the vent area under the hood under the windshield wipers.  What should be our next step to trouble shoot this problem?  Thank you.