youth fishing

Fishing salmon w/my 9 year old son & 2 pole permit

1) Can I hand my pole to my son to allow him to fight the fish (or do I need a 2-pole permit - see #3)?
2) Can I cast out the line for my son and then let him hold the pole?
3) If I purchase a 2-pole permit, then this would allow me to cast out another pole and then let my son hold it?

Just trying to get some clarity on what is allowed with helping my son fish.

I understand that my son can purchase his own salmon tag. If not, any fish he wishes to harvest would go on my tag.