There are many resources on the web for growing hostas from seed, but regardless which method you prefer......  it is very easy!

You will need a clean pot or seed tray, peat moss, vermicilite, and your seeds.  Fill container 3/4 full of peat moss, place seed on top then top with a thin layer of vermoculite.  Keep soil moist, not sopping wet.  Once the seeds germinate and grow to a stage of having 2 - 3 leaves you can plant them outside to grow.