It is just about the right time to start sowing, your French Beans indoors. I always start mine indoors by sowing each seed into a small pot of a good quality multipurpose compost After sowing water them and allow the pots to drain. Place them on a warm windowsill until the beans germinate.
Alternatively if you want to waiting a bit longer then you can sow them outdoors in May. I sow two seeds together straight into the ground in rows, spaced about a two feet apart with the beans planted about 20-30cm apart. But dont rush if its still too cold and wet, allow the soil to warm up a bit first.
You should be able to start harvesting from July :)