Asparagus update-conundrum

So I have the lacy ferns and a couple asparagus-like shoots are coming out. I don't know what to do next. Do I eat them? What if I need them for later? What if, when I harvest them, I'm actually killing the plant? What if the first couple are poisonous? How many aspargus will eventually come out? I only have three seedlings--what if that only makes three asparagus? And then I'll have three asparagus a season for fifteen years. Strangely enough, I can't find the answer online. I know, right? I even looked in a--get this--book. No dice. I've found that, a lot of times, written materials only pretend to be instructional, when actually you have to know something about the subject matter to use the information. If I knew, I wouldn't need a book, now would I? I'm probably going to have to buy one of those The Complete Ignorant Asshole's Guide to Asparagus, though first I'll have to get past the feeling of complete ignorant asshole-osity that attends needing a book like that.