Hi,
I basically cheated and ordered a whelping kit from these people
Whelping kits | Whelping boxes | Heat pads from Petnap Ltd | kittening it had everything I needed pretty much, I also ordered extra training pads from them as you tend to change these regularly. Keep a note pad to hand for jotting down weights etc,definitely phone with vets number easy to hand.
The thing used the most was the antibacterial hand wash. I also would say bin bags for getting rid of messy pads. The nutridrops are good to have in as an emergency. When we were nearing the end I gave Mum a raw egg whisked up,seemed to give her energy right near the end.
Hope it goes well.
Izzie