How to research private companies?

Does anyone have any tips for finding information on privately held companies? I generally start with Google but it normally doesn’t get me that far. Just looking for some extra tips or if the few tidbits I can normally get from Google are all that I’ll get. Thanks.

I think it would be tough unless you know management well enough for them to allow you to view their financials. Even then, I’d think you’d have to be a serious potential investor for them to release the information.