Asparagus can be grown from seed but Gardening or Farm Stores will recommend planting "1 year crowns". I quite agree as the harvest time is moved one year sooner and the crowns have already germinated thus reducing the odds of failure. These same stores will likely instruct you to dig a trench (usually 6 or more inches deep and 12 inches wide by 2 feet in length for each crown).

Asparagus needs good drainage and fertile soil with a neutral ph. of 7.0. Some suggest adding 1 inch of soil (or compost) every month or so until the trench is filled or 2 inches over the crowns and add 2 inches every year. I choose the latter but not the trench. My soil is rock and clay, weeds don't even like it. It will not drain water, it is not fertile and also very difficult to dig. The answer was a raised bed.

First mix compost into the area that is to be the location of the raised bed (my dimensions are approximately four by eight feet), a flat level area is best. Then using Pressure treated 2 x 6 s about eleven inches high and an inch and a half thick, build a box 42.5 x 90.5 inches on the outside. Make sure the diagonals match to insure that the box is square. Then position 2 x 2 stakes at the inside corners and half way down the sides and drive them into the ground. Next, to isolate the pressure treated lumber from the soil, line the bottom, inside and top of the box sides with plastic (a type that won't leach into the soil and also will prevent the pressure treated lumber from doing the same). Leave the center of the box uncovered and open to the soil. You may attach the sides to the stakes from the outside using short screws to avoid damaging the plastic liner. Add a seat for comfort by cutting 2 x 6 s to create a 4 foot by 8 foot frame that can be attached to the top of the box. Looking down on the box, It will look like a picture frame. (I planted ten crowns in my box)

In Upstate New York, "Mary Washington, Purple Passion and two Jersey Varieties" were recommended to me. I have been very happy with the results.

Plant your asparagus and fill your box by whichever method you favor. Wait at least two years to harvest from crowns and three years for seeds. Stop harvesting before July in most areas and allow the tops to grow as it strengthens the crowns. Add soil (compost) in late fall or very early spring.
Start to enjoy fresh asparagus from your garden, steamed or roasted with butter or Hollandaise sauce. Maybe Eggs Benedict or Ham-Asparagus Strata would suit you better. Yummy.

Asparagus can be frozen. It must be blanched in boiling water, cooled, somewhat dried and placed into freezer containers. If using freezer bags remove as much air as possible. Charts are available in cookbooks and on the web. Time for boiling is based on thickness of the spears. Always snap or cut off the hard woody part and wash before boiling or cooking. Use a processor or blender to puree the removed parts, then strain and make a cream soup with the cleaned pulp. Waste not, as there are a lot of recipes.