Seeing as how we just did what you are going to do, heres the low-down,
Yes you get your visa in the american consulate chicago, nyc or la. you get it that day, if you have all your ducks in a row. pay online and submit your application via e fast track really speeds things up! Yes as soon as you have that "golden ticket" you as the american can legally work. What we chose to do was for me and husband to stay here and then fly over together in may. We secured a place at his rents for a couple of days with proof of their mortgage to the officials, and showed we have savings to live on until we were employed, and they didnt seem to have a problem with him not already having a job,. they just wanted to see his employment here, and that we werent going to live off the government when we got there. the chicago consulate is where we went, very friendly people, and mon-fri from 2-430 they answer any quetstions over the phone that you have .
hope this helps and good luck,
oh by the way yes it really is that simple, I didnt believe it either when people said it, but yes coming from one person who JUST got her visa on Tuesday, it realllly is that simple.