Congrats and well done, my G/B twins are 9weeks and we still getting over the shock!
Be prepared to get big (really big) and tired, lukily I had no morning sickness but I used to sleep for hours. Do your pelvic floors!
At the hospital just be relaxed and go with the flow. I had a birth plan but we all knew it was a joke and I would be doing as I was told. I had the first normaly and the second c-section at 37 weeks. I was scared but I trusted the MW and that helped. I talked through all the possible birth scenarios with the Dr's.
Get some help in. My mum came and lived with us the first month and his mum the second. We have an older daughter 19months.
Car seats - get whoever to put the ones you want into the back of your car so that you can see if they all fit. Halfords did this for us, even though we didn't buy any that day.
I kept the DD in nursery for the first month or so and that took off a lot of the pressure because I knew she was being looked after and we could sleep when we needed.
Don't be afraid to turn people away, particularly if you know they are going to be hard work. As much as you love friends and family you will need your energy for the babies. And the friends that turn up and do housework or make you lasagne are the very best.
I have a great second hand buggy and friends who have boys gave me lots of clothes. The girl is already supplied. I found out the sexes before they were born. I also went to the hospital with different sizes of babygrow because the weight from the scan is only an estimation.
Get organised, get your necessary equipment before they are born and be prepared to not see the outside world for a little while.
Get your shopping delivered! We buy loads of nappies when they are on special offer, you get through so many.
The first time they smile at you is just so amazing it takes your breath away. They have been hard work but holding them is just the very best.
Hope this helps