The concept of a go bag for the hospital also was very important and would have saved four or five family trips to our place.
Get the most expensive peri bottles you can, not the hospital ones.
More people than you think faint during the birth, if you're sensitive, prepare to fight your parasympathetic system. Do the breathing exercises regardless of your role!
I was completely outside time and space for two weeks, very tired for four months and it took 18 months to feel as sharp as I did pre birth and I was the support system not the main character :)
Get a really long phone charger for the hospital, naturally the plugs around the bed are used by machines but not the far away ones. Naturally they don't have them on site so bring your own.