Here's a few things that work very well for us and our 8 week old kitten, Jupiter.
1. Blow lightly on the kitten's face, it will stop biting immediately.. they get a cute, confused look on their face too.
2. Replace the focus of attention with a cat toy, this usually works every time.
3. Take a light washcloth and gently swipe the kitten, this works very well too.
I find using spray bottles only scares the kitten and can make them fear you and not grow mentally stable as cats, so stay away from severe treatments or punishments!
Above all, your kitten doesn't understand you're not playing, they're too young, they're your babies, try to be patient!
Look at his first pictures, finally online isn't he adorable See Jupiter in all his kitty glory