For your fog lights you can wire them to come on with the headlights, or the parking lamps or however you want, with or without a switch. If you want to wire them to come on with the headlights or the parking lamps you need to use a relay, that will ensure that you don't cook you wiring. Do some online research and see what you can find out, there's a lot on the internet about it, it's nothing hard to do either. Basically, on a standard automotive relay you have four connections that are numbered: #30, this is the fused circuit from your battery, #86 the relay's ground, #85 the relay's trigger, i.e. the parking lamps or headlamps, and #87 the connection to the fog lights.