I usually give mine vitamins for the first few days after hatch, as a boost, each person will have there own preference, I just don't think it's needed after that unless the babies are acting lethargic. For vitamins, I'll sometimes use either Rooster Booster, Nutri-Dench, Sav-A-Chick, or Poultry Cell, all are great brands, out of all I would say Poultry Cell or Nutri-Dench gives them the most vitamins.
If they are a week old, you could probably provide them with a shallow container of water.
I keep around thirty-five birds as pets for the last five years, I've had lots of experience with different things, but BYC is a great resource for anything poultry as well.