speedo & ABS brake lite problem

Hey fellas, I am having trouble with my 2000 Chevy pickup, 2500 with 454ci eng., auto tranny. The speedometer doesn't move until about 20-30mph. Then when it does it is real jerky as it rotates up. At the same time the ABS lite on the dash comes on and the brakes feel like they start dragging. My repair manual is not clear about trouble shooting these symptoms. It hints at the Vehicle Speed Sensor on the tranny as suspect. If anyone has had these problems or knows solutions please respond. Thanks Les.

I would also suspect the VSS. Or possibly a wheel sensor, causing the ABS to complain.