Hi Lotty Lou,
I am sure that you will see lots of helpful advice if you use the search function on here or google it. But What i would suggest is that you pot the 5 crowns up in nice big pots. Its going to take a while to get an asparagus bed ready.
They are in the ground for a long time and are hungry.
You need to dig a big deep hole, and it need to be filled with layers of well rotted manure and sand and compost. Plant the crowns onto and into compost. Mark the crown with a bambo steak so you know where you planted them in the future. You will get a crop in 2 years :-)
cambourne7