How can I eliminate moisture dripping from my ceilings?
The most likley cause of the moisture is too much humidity.

Some solutions:


A dehumidifier 
Fans to vent/move air around (to outside)
Increased Insulation in the attic (to avoid a large temperature difference between the ceiling and the attic)


Basically the humidity needs to be lowered inside the house.

You can get a Hygrometer to measure the humidity to see where it is at.  If it is above 60% then its definately a bit humid.