Growing Calla Lilies?

I ordered calla seeds. I received small bulbs some with shoots. The size is about 1/5" to 1/3". I planted them in a plastic tray each individually and covered with a dome to create a medium for growth. I don't know if I did the right thing. I also put them in a cool dark place. I got them in small plastic bags without instructions. Please help. I am starting a garden and probably need professional help. I live in zone 8.