No running water, replaced pressure switch on pressure tank, have power but tank won't charge... HELP!

The main question you need to address is this: Is the pump coming on? Check your switch and see if the points are closed (touching). If so, then is this pump above ground or in the well? If it is above ground, then it's easy to check and see if the pump is cutting on. If in the well, you can probably just feel the wellpipe and see if you can detect a slight "humming" vibration to see if the pump is running.

I am, of course, assuming the breaker is turned on and the pressure gauge is reading at or near zero.