Play biting is normal behaviour for kittens, but they don't realise how sharp or hard their bites can be!
If your kitten bites your hand during play, end the session immediately. Don't jerk your hand away - your kitten will see this as part of the game and your hand as a "moving target". Avoid games where your hand is acting as the object of prey - play with balls and toys so your kitten can learn to safely redirect their natural instincts.
All pets respond far better to positive rather than negative teaching methods, and this is particularly true with cats. Never scold, or hit your kitten for any reason - your kitten will instinctively want to get away from you, and will only learn to be scared of people.
Your kitten may also bite if they are touched in a sensitive spot. If your normally serene kitten has suddenly started biting, see your veterinarian to ensure there are no underlying health problems causing this change in behaviour.