That's a fairly broad question. But here are a few places: http://www.business.gov/expand/business-data/specific-industries/ Also, you might want to consult with your local SBA office. However, it's hit or miss as to who you get to help you out. So, if the first person you meet with doesn't seem to be working out (or doesn't seem to have the expertise for what you're trying to find), I'd recommend coming back later. http://www.score.org would be another resource worth starting with. Can you give more details about what you're looking for?

If you have a university nearby, their libraries have access to numerous subscription-only databases containing a wealth of information. Public libraries in larger cities also subscribe to on-line databases. I am able to access the databases at my public library from my home computer simply by in-putting my library card number.

Thanks for jumping in with those great tips, guys! We recently posted an article on Business.gov that helps small business owners navigate the free government data and statistics available on the web - here is the link: From Consumer Spending to Wage Data for your Business Type – Free Government Data at Your Fingertips

Apart from looking at government data (as mentioned in other posts), you might want to investigate companies in the sector as they are your soon-to-be competitors and their statistics could tell you a lot.