My beautiful Zippy died on April 17th. She was a little over a year old, but I had taken care of her since she was a kitten. She came up to my house all skin-and-bones, and scared of humans. She had some burn marks on her, and I assumed that some kids had been torturing her. So I took her in...
Oh, and to kind of add to what wookie130 said, by week four they definitely should be able to learn how to go to the liter box on their own. I use a paper-based kitty liter, so that way I don't have to be afraid of them eating the clay clumps in normal liter.
I am in the process of weaning my own little kittens. They didn't really want anything to do with solid food, so a friend told me to try using Gerber's lamb-flavored baby food (but only use Gerbers or Beechnut, because other brands have a certain ingredient in them that are bad for kitties). I...
She might have mastitis. If this is the case, she must be taken to a vet immediately. I lost my beloved Zippy to mastitis a week ago, and I thought she was just a little sick...
Here's a link to more info about mastitis:
http://www.cat-world.com.au/MastitisInCats.htm