US publications offer a wealth of investment and finance data

Information can be a precious commodity in investing or making other personal finance decisions. The trick is to find the right facts quickly. The federal government is often overlooked as a source of such information. Federal agencies produce piles of documents on financial and consumer matters, and beyond these publications is access to the experts who write them.

So how do you find answers in this mass of available data? Some options: Hire an information consultant (expen-sive but useful for complex searches), call one of the Federal Information Centers set up to help you find things, or head for your public library, where reference librarians can point you to the publications you need.

Here is a sampling of government resources you may want to get acquainted with. They are among the most heavily used publications in the Chicago Public Library's business section, says reference librarian David Rouse.

* 10-K reports - These documents, which companies must file with the Securities and Exchange Commission (SEC), contain more detailed information than is usually provided in the company's annual

report. They are consulted so frequently at Chicago Public Library that 10, 000 to 15,000 microfiche (microfilm cards) showing 10-K information are refiled each month. You also can get copies of 10-Ks by writing or calling the SEC, Washington, D.C. 20549, (202) 523-5360, and paying duplication fees - or by visiting SEC reference rooms in Washington, Chicago, New York, or Los Angeles.

* Economic Indicators - This monthly publication gives information on prices, wages, production, business activity, purchasing power, credit, money, and federal finance. It is a window into the current condition of the economy.

* US Industrial Outlook - This volume looks at the prospects for growth of over 200 individual industries in the United States. It is useful in deciding which industry groups are good investment prospects.

* County Business Patterns - This annual publication provides employment and payroll statistics for specific industries within each US county.

* Official Summary - This is a monthly summary of security transactions and holdings reported by ''insiders,'' those officers in corporations who know facts not available to the public.

Other heavily used titles published by the government or containing government data include Statistical Abstract, American Statistical Index, Occupational Outlook Handbook, Overseas Business Reports, Foreign Economic Trends, Franchise Opportunities Handbook, Monthly Labor Review, and Construction Review.

You can order many of these publications through the Government Printing Office or see them at your local library, if it is designated as one of the 1, 370 Federal Depository Libraries or maintains a less complete government documents collection. You can get a list of Federal Depository Libraries by writing the Superintendent of Documents, Washington, D.C. 20402.

Government documents are often kept in a special library section. Robert Baumruk, head of the Chicago Public Library's government documents section, notes that readers are interested in Internal Revenue Service regulations and rulings.

''They often want to look up the rules on IRAs (individual retirement accounts),'' he says. ''They want to see them for themselves.''

Other popular documents are social security materials and the Code of Federal Regulations, which contains rules on obtaining various kinds of government benefits.

Even with all the information on paper from Washington, you may want to talk with an expert in a particular field. And the government has an expert in just about every field. You find the right name and call. But when you do, he or she may deluge you with more information than you want, because some of these experts spend their careers assembling information that is seldom requested. Also, government experts have to be nice to you. The Civil Service Reform Law requires these experts, as well as government employees generally, to be polite to private citizens who call.

How do you find the right experts? Since the federal government is expecting you to call, it has set up a National Referral Center in Washington to handle such requests. Data banks in the NRC list some 13,000 governmental and corporate sources of information, and the agency publishes a number of free mini-directories. Write National Referral Center, Library of Congress, Washington, D.C. 20540, or call (202) 287-5670. Closer to home might be one of the Federal Information Centers maintained in 37 cities around the US. If there is one in your area, it will be listed in your telephone directory.

If you know which agency might have the information you need, you might call it directly. ''We get a fair amount of requests for information by phone or letter,'' says Nancy M. Goodman, assistant vice-president for information services at the Federal Reserve Bank of Chicago. ''We try to provide them with various informational publications, but we have to steer a fine line on investment information. We try to be simply descriptive, because we do not feel we are in the business of advising people on how to handle their money.''

In addition to referral services within the federal government, several information professionals have written special guidebooks to the maze of government information. Two good ones are ''Information USA,'' by Matthew Lesko of Washington Researchers, and ''FEDfind,'' by Richard J. D'Aleo.

* US Goverment Books - This is a quarterly catalog listing some 1,000 or so of the government's ''best sellers.'' It's available at no charge from the Superintendent of Documents, Government Printing Office, Washington, D.C. 20402; telephone (202) 783-3238. It is also available at the 24 bookstores the GPO maintains around the US, along with bibliographies listing everything available on particular subjects like business and finance.