I don't know much about raising a kitten, but I've heard that it's not a good idea to take a kitten before they're at least 10 weeks old, preferably 12 weeks. They get some very important nutrition from their mom which gives them a stronger immune system, and they also learn a lot from her in this period. However, it can sometimes, for various reasons, be neccesary to take the kitten away from her.

The links KL posted seem to have a lot of good info, so I' sure you'll manage.

Good luck!