it is hard to say how long to cook it, because thickness makes the difference. Plus I like mine slightly crispy, husband and my father want it much softer. But my favorite is to snap off the ends (or peel if you have patience), then immerse in boiling water (best with a squeeze of lemon in the water). While boiling, I make a dip of mayo, a dash of mustard powder (or a bit of Dijon, not a lot, just put a spoon in and add what is clinging to the spoon), honey (ditto the above, just a bit) and another squeeze of lemon. Then you can either pour the sauce over the asparagus, or better yet, just serve it and use it as finger food, dipping it in the sauce.
If you have freezer space, don't toss out the trimmings, just dump them into the pot when making stock.
Cold asparagus is great in salads, or in an antipasto plate. Also, if it is thicker stalks, you can (after steaming, boiling, roasting) wrap your favorite thin sliced ham around the stalks for an elegant appetizer (I'm sure some would say it has to be proscuitto, but I've lived in so many great ham-making places in the U.S. that I think you should go with what is great where you live).