Great places for Kitesurfing in Greece include Rhodes, Paros, Kos,
Karpathos, Naxos, and Crete,
among others.
Personally, I think
Karpathos is the best island to learn
kitesurfing because the chance of wind is high, you have a lot of space
in the water and there are only few other kitesurfers next to you.
The main kitesurfing season runs from May to September. This is due to
water temperature, wind direction, and wind strength.