IF you already have an older cat in the house show him/her that he/she is superior to the kitten. If this does not happen the older cat will grow to hate the kitten.
Kittens love attention and want as much as possible but if the older cat is in the room, you must pay attention to the older cat. Even if you want to pet the kitten you must pay attention to the cat.
Kittens don't need as much food as older cats so you really only have to feed them when you have meal times.
Kittens are very entergetic animal so you can not keep them capitve in your arms, they will hurt themselves. Also keep anything off the floor that you don't want broken. They tend to play with them.
I know this things because I myself have a kitten and cat. When they first saw each other they hissed and spit, but now they are best buds that only get on each others nerves sometimes ;D