We booked the CP dinner package with Chefs de France....you can book them as soon as they are available to book. Keep your eye on wdwig, or these boards and you will know when that is.
When booking, the only thing I recommend is making your ps a little earlier than you would want....Chefs de France was so full the night we were there...we were seated very late and had to rush through dinner in order to make it to the CP on time. Our seats were still fine...as we were guaranteed seating...but, rushing through dinner was not too much fun...as Chefs de France is a great place to eat.