SFoodie ended up asking a lot of people that question over the course of the next few weeks: S.F.'s environmental health division, directors of several organizations, and several Underground Market ex-vendors themselves. Some of these vendors are trying to go legit, but are mired in a morass of conflicting information. Others have already made it through and are operating aboveboard.
So over the course of this week, we're going to try and spell it out: Here's what the city, the state, and the country want you, o aspiring pickler or scone baker, to do if you want to start up a microbusiness. Hint: You're going to need to be committed, and you're going to need some seed money — not a lot, but a lot more than $50 and a free Twitter account.