Shaking steering wheel

Hey everybody!
I have a 1990 Honda Accord Wagon that I got from my dad’s estate. I had 40K miles when he passed away and now has about 80K. We have kept the tradition of maintenance: new oil every 3 to 4 k, new tires, brakes, and general service. Lately the steering wheel has been shaking. It seems to be worse when the car is in drive, and not moving. It seems to be slightly worse when the AC compressor comes on. It seems to smooth out considerably, though not completely when the car gets moving. I listened to an episode on Car Talk, and there were several major items to have checked, but I cannot remember them all. I did have the care “tuned up” and had the motor mounts replaced (one of the few items I could remember.) What else am I missing. any input would be greatly appreciated.