Kitten Teeth

Hi I have two questions about kitten teeth.

1). at what age do their kitten teeth fall out and the adult teeth come in? What should they be allowed to chew on while teething? When the adult teeth are coming in is the "teething" process the same?

2). I have heard it's bad to let them bite your hand when you're playing with them but is it also bad to let them lightly nip your fingers (not necessarily when they're playing but when they're relaxing)? Or are these two things the same?

(OK I guess that was more than two questions! LOL) Thanks!

iv always found their adult teeth start somming through when there about 5/12-6 months old.
i never needed to give any of mine anything special when teething, they just chewed on their toys a bit more then normal.
and yes you shouldnt let them play with your hands, as they get older it will become a problem and WILL start to hurt, you should just leave your hands as the one who strokes them not as a play toy.