Well, I know the name of the company, where it is headquartered, etc.
If it is listed on NASDAQ or NYSE, you can go to a number of sites and search by name. Yahoo Finance is one of dozens. Just type in the company name.
Is this a publicly traded company? If so, you can lookup the ticker symbol.
If not, you’ll need to contact the company itself, or the state government office where it’s incorporated (usually the Secretary of State.)
You could start here.
Also etrade.com
You’re a funny, funny fellow.
finance.google.com works pretty well for me.
NYSE.com allows you to search by company name.
If it’s a publicly traded company, you can search their EDGAR filings at the SEC’s website: http://www.sec.gov/edgar/searchedgar/webusers.htm
… and a correct one, as it turns out.
Hoovers can also show you some information on companies that can help you determine if it is publically traded or a private company. They also can tell you if a company is a division of another larger company.