While I remember, here is a list of things that I found kind of useful for the hospitalness. They might only be good for me, or only a concern if mum & bub are there for a bit, but thought I'd write them down while I remembered.
* note pad and pen.
Dear god, make sure you have a palm sized note pad and couple of pens. Every 20 minutes people will come and tell you something, and you won't have a brain that is able to hold onto the information. But for the support person specifically, it is a fabulous thing to get home late at night and have a List. The list means you will know what needs to be washed when you get home, what you need to buy from the shops, and what you need to bring the next day.
There was also a bit of value in using it as a daily planner - writing "THURSDAY" at the top of a page and then a list of things that would be happening during the day.
Hospitals are the right temperature for babies and mothers in nightgowns. For anyone else they are a slow death through dehydration. Take along a bunch of gatorades or whatever, and then use the bottle for water. This is also good for mum so she doesn't have to keep getting up and down.
* paper and pen.
Its not really the right word, but I can't think of it :) Basically mum & bub are the patients, and so the staff will concentrate on them. You're just a privileged visitor a lot of the time. I noticed one person while we were there try and answer all the midwife's questions and generally be in the way. I think he had the best intentions, but its not really a good idea. Get mum to ask the questions you have if you think of them in between visits of staff (see paper&pen), or wait until there's a lull in the rest of their interactions before asking it.
* a book
There may be times when mum is catching some sleep, or you're just not needed, or simply need a break. Grab your book, get a hot beverage of choice, and go outside for a break. You'll be better functioning for everything else.
* phone charger (and credit for prepaid)
You may well be acting as the gatekeeper for all communication - this can lead to a certain attrition in battery power and phone credit on the mobile. Box Hill had powerpoints around the bed for patients to use, we just whacked the phone there.
It was mostly the paper and the drinks that caught me a bit offguard - I wasn't expecting my brain to turn to such mush, and being able to return to secondary memory was a lifesaver. And the hospital is only _slightly_ too warm, and a bit dry, so the drink thing snuck up on me.