Wiring Question

This isn't as much of a track wiring question as a purely accessory wiring question.

This is my first layout so I bought the Bachmann EZ Track pack which comes with the basic directional controller. It has two opening at the top labelled accessories so this is where I put the wires for my switches.

Now I have about 6-8 buildings with lighting. What kind of power source should I run these wires to and do I have to change out my power pack? Beacause I would much rather keep the wiring separate if I can from what powers the track and what powers the lights so the lights won't be running everytime the train is running.

I know this probably seems so simple I'm just not good at the technical and electrical part of all of this.