Most setups I've seen are wired so that the pump and fan are on when the ignition is on. I don't have a fan for mine, but that's how I wired the pump.
I also need to update this. I ditched the radiator cap and added a small reservoir with a vent. The system kept pressurizing and then leaking all the fluid out. Once I added the reservoir, no more leaking. It also made the pump much quieter. I think the way I had it before would never quite get all the air worked out of the system and it made the pump noisy.