If you don't know any lawyers, this is very tough. If you do know lawyers, then say "I'm debating starting a company, can I take you out to lunch and get your opinion on a few things?" Then take them out to lunch at a nice place, and ask them a few questions. Whatever you do, don't waste time, so read up about starting a company before you meet with them, and don't ask them to do any actual work for free.