They will give you the Birth Certificate, FTB and Baby Bonus papers at the hospy. It needs to be stamped and signed by someone at the hospital to be accepted. They stuck mine in the little plastic crib when I was transferred to ward all 5 times. Anything else make sure you have the paperwork in your bag before hand.

They may well go from date of babies birth for the baby bonus at least, but I have only ever known them to take it from the day of first contact with FTB A. It is best to be prepared and get everything in ASAP just in case.