I love growing this variety of spinach (perpetual) as it does not bolt (like starts to flower or seed) easily as spinach. They are easy to grow as it will grow anywhere where there is not much sun.
Sowing the seeds are quite easy as they germinate quite quick.
Just harvest the leaves only as they grow so there will always be a continuous supply. I bought the seed online from ebay shop. Mine at the moment, are still young and the slugs have been feasting on them recently so do protect them from slugs.
I have a easy to cook recipe on making Spinach omelette recipe There are lots of uses of spinach in salads, pasta, pizza, stir fry and plenty more.