For the relay wiring, on the relay the terminals should be labled with numbers (30,86,87,87a,85)
30 to the battery
85 to a switch that shows 12v when on
86 to chassis ground
87 ouput to the foglights
87a not used
Most relays are only rated to 30 amps, so make sure the foglights dont pull more than that. It may be neccesary to use seperate relays for each light. Depending on the current draw of the lights. Easy way to tell the current is dived the wattage by 12 and thatll give you a rough current draw.