Ok firstly, do not disturb the nest at all - this can stress mum and she may abandon or cull the pups, just keep her nice and quiet - only going in to put down more food.
Good food for mum and the babies are cooked chicken, milky poridge (make with kitten milk or water and a tiny bit of regular milk) baby food (that comes in jars or tins that have no herbs, spices or garlic), cucmber, brocoli, carrott, and an unlimited supply of their regular dry mix. The softer food will go down well with babies when they start to wander out of the nest aswell.
Have a good look at the breeding section here and the wiki, these is lots of good information on pups and bringing up a litter. Did you hammy come from the pet shop pregnant, or was it a planned litter?
Any other questions just ask - there are many experinced breeders here (I must confess I am not one of them, but have picked up the basics along the way!)
Good luck with them anyway and welcome to the forum