I am going to counter this advice, and say first thing you do is gauge interest, start the conversations, let them push for it. When things are obviously starting to solidify and are getting serious, then consult with an attorney.

I just went through this situation last year, and while taking legal advice early on is good, it's very easy for lawyers to get their share of money. If you already have a relationship with a lawyer, sit down with them for an hour and get an overview, but don't have them do anything like draft documents, review dialogue, etc. They'll want to do these things (billable hours) but they'll just cost you a ton, when 95% of the time the deal isn't going to happen anyway.