I recently adopted a kitten who was, at the time, about 5 weeks old. She took to being in the house right away. We started by keeping her in the main part of the house until she got used to her surroundings. Then little by little gave her free reign of the house. She doesn't even seem interested in going outside now.
The feeding is a little harder. We started by bottle feeding our kitten milk. Also fortifying her food with a kitten formula that petsmart recommended. She seemed to take to regular eating patterns within about a week. She now eats out of her "own" food bowls.
The litter box was also fairly easy. EVERYTIME she ate something, we immediately put her in her catbox. She picked up on that immediately.