Freelance writers can get a great deal on Lexis Nexis, which is where corporations go to get research on any topic you can possibly imagine. Normally it's too expensive for mere mortals, but if you go to expertaccess.org, you can get it for $19.99/month.
I just signed up and got this message: "LexisNexis has given us only a limited amount of time to prove there's a real market with independent professionals. If there are people you know who might need the service, please let them know so we can continue to provide it at this low rate. We're also working to provide additional services like CourtLinks and Public Records. To do this we need as many people to sign on as possible. So please do spread the word if you feel Nexis access is valuable."
So I would encourage you to check it out while it's still available.