Karen, I agree that your climate should be fine for the asparagus. I don't think you want to put in 60 plants, but you might want more than the 6; I think I have about 30 (or maybe more like 25), and we get LOTS (as in, it's about the only vegetable we eat for a couple of months other than salads, and I also pickle some for use in Bloody Marys -- yum!). I'd suggest maybe 12 or 18 plants for a nice little patch, depending on the space available, of course. And I would plant the roots maybe 4" deep or so, meaning 4" of dirt on top, not 4" to the bottom of the hole. Make a little mound of dirt in the bottom so you can spread the roots out over it, kind of pointing down. The recommendation years ago was to plant considerably deeper than that, but they seem to seek their level of happiness on their own. And yes, unfortunately it takes at least until the 2nd year or possibly the 3rd; the general rule of thumb is to not pick anything smaller than a pencil. Let the fronds grow and feed the roots over the course of the summer and then cut them down and dispose of them in the fall, as well as cleaning up the ground under the plants, to help eliminate pests -- keep a close eye on the plants, especially early in the spring, for asparagus beetles -- they can really do a number on the plants, plus they will lay eggs on the stalks that you want to harvest, which I don't find very appetizing even though it's easy enough to wash them off. If you have compost, throw some of that into the planting holes, and I fertilize at least once a year with a balanced fertilizer. I also use a mulch of grass clippings in the paths and between the plants, which helps hold moisture in the ground for them and helps control the weeds. All of that is a lot easier to actually do than to type out, it's really pretty care-free compared to a lot of the garden plants !
and my "attempt" at a bed goes back at least 10 years. Let it grow you will harvest...graze at first sight and for get it. 
(it's my "no plants left behind program" ...)
