thoroughly clean the paneling remove all electrical plates do any filling in of holes, dings and diviots with spackle or caulk, paintable caulk of course. tarp it out. Now, get a good Zinser brand primer, latex preferable and apply two coats of this. Now after dry, apply the finish coat, two coats.
Not too much to it.
If the color to be painted is white, then prime with primer out of the can. If the color is any other, then tint the primer to match the color and this will get you a good finish faster.