Plant them as soon as you can, with twice the bulb's height of soil above them, and the leaves on the surface. Water them in well, and give them some liquid tomato food at the same time. Let the leaves die down naturally - don't cut or tie them - and remove them when they've gone brown, making sure that you fill the small hole left when you remove the leaf (leaving a hole will allow narcissus fly to get in and kill the bulb).
They should come up for you next year - mark their spot so you don't dig them up by accident.
