Picked the first amount of green beans today, here's how to freeze them.
Cut off the heads and tails, and either slice or cut into 2inch lengths. Bring a pot of water to the boil, and dunk the beans in, boiling about one minute. Drain in a colander and run with cold water to stop the steam when freezing.
Cover an oven tray with tinfoil, and lay the beans in a single layer on the foil. Put into the freezer overnight, and the next day pop into a bag and back into the freezer.
You can then use them as and when you need, without defrosting, just pop straight into boiling water for a few minutes.