Question
We lost power for 20 hours. When the power was restored the well pump was running, but no water pressure showed on the gauge and no water ran in the house.  Do I need to reprime the pump and if so how is that done?

Answer
Honestly, it would be best if you have someone look at the pump to determine what it needs.  There could be any number of problems that may go unseen without a good going over.  However, if you want to prime the pump, and it is a jet or centrifugal pump, there should be a removable plug on the intake side of the pump.  Remove it and begin filling it with water.  Once the pipe is filled with water, replace the plug and turn on the pump.  THis is how I have done it with my setup.