To determine how healthy and promising a company is as a possible investment, you will need to do some digging into it. Here are some online resources that can help. If you are computerless, consider reading

The Little Book That Beats the Market

by Joel Greenblatt or

The Little Book of Value Investing

by Christopher H. Browne (both Wiley, $20).

The company's own Web site. Look for links labeled "About Us," "Corporate Information," "Investor Relations," etc., and try to read through at least the most recent annual report. Even a "Career Opportunities" section can give you insights into how heavily it is hiring, what kind of people it needs, and what various employees do in their jobs. Search engines such as Google.com can help you find a company's Web site.

Online company-data providers, such as

» READ MORE: http://quote.Fool.com

and

» READ MORE: http://finance.yahoo.com

. Financial statements that companies must file with the Securities and Exchange Commission (SEC) are available through such sites and also at

» READ MORE: www.sec.gov/

edgar.shtml.

Analyst research reports. Most major online brokerages (such as E-Trade Financial Corp., TD Ameritrade Holding Corp., the Charles Schwab Corp., Fidelity, etc.) offer customers access to a range of Wall Street reports on loads of stocks. Learn more about sorting out brokerages at

» READ MORE: www.broker.fool.com

.

Historical P/E ratios and other measures. Look these up at sites such as

» READ MORE: http://

moneycentral.msn.com. Just type in a company's ticker symbol, click "go," and you will be able to find gobs of data on it. Historical numbers can be handy. If a company you are examining has a P/E of 22, for example, and you see that over the last five years its P/E has usually been around 30, then you might be looking at an attractive price right now.

Insightful articles on companies that interest you in current issues and archives of financial periodicals. These include the Wall Street Journal, Fortune, Forbes, BusinessWeek, SmartMoney, Barron's, Investor's Business Daily, the New York Times' business section, The Economist, etc. You can read many of these online for free. Your local newspaper's business section can be informative, too.