Rabbit gestation is 31 days.
Does usually start to build a nest somewhere between a week and two days before they have babies. It's VITAL that you give your doe a nest box as soon as possible to keep her kits from wandering away, chilling, and missing meals. Any small box will work, such as a small plastic bin without the lid. Avoid cardboard if possible, as the doe will chew it and it will absorb urine. Pack the box with hay and give her additional hay with which to build her nest.
Also, if the rabbit is still with the dad, remove him right away. He can harm the babies and will breed the female back as soon as she gives birth.
I just thought I should let you know that first-time moms often lose their litters, at about a 50% rate. They usually do much better the next time.
Also, it's easy to worry about whether your doe is feeding her litter, but she almost certainly is. Rabbits only feed their babies once or twice a day. This is to keep them safe in the wild, by not alerting predators to the location of the nest. It can take a few days for the doe's milk to come in. This is normal and protects the female from mastitis should the litter die. Kits can live for 72 hours without eating! Do not intervene and try to hand raise the kits unless absolutely necessary, because it is usually unsuccessful.
This website walks you through baby bunny care and gives plans for building nestboxes: http://thenaturetrail.com/Breeding-Holland-Lops.htm
6+ years of breeding rabbits; American Rabbit Breeders Association national runner-up Queen;
ARBA raising rabbits handbook