How to choose investment guides; Dun & Bradstreet's Guide to Your Investments, by C. Colburn Hardy. New York: Lippincott & Crowell. $14.95 in hardcover, $8.95 in paperback; How to Beat the Financial Squeeze: Don't Get Mad -- Get Even, by William G. Flanagan. New York: Doubleday. $10.95; Seer or Sucker: How to Deal with Inflation in the 1980s, by Carl E. Andersen. Boston: Halebrooke Press. $10.95; The Hidden Stock Market: How to Pick $5 Stocks That Can Double in 6-12 Months, by Dr. Ira Cobleigh. Norwalk, Conn: Executive Planning Center. $19.95 (plus $1 for shipping).

So many books on investing are to be found on bookstore shelves that it is tempting to say they come a dime a dozen -- except nowadays they cost $10.95, $ 12.95, $14.95.

All this advice on how to get rich makes one wonder if it isn't more lucrative to write these books than to follow the advice in them. Why, otherwise, go to the hard work of producing 300 pages of prose about stocks, bonds, commodities, futures, real estate, precious metals, options, mutual funds , tax shelters? But probably that is being overly skeptical, since undoubtedly pride, prestige, and satisfaction enter into the motivation of authors in this area.

The books themselves vary greatly in quality and coverage. The best buy of the books in this grouping and certainly the best for the serious new student of investments is C. Colburn Hardy's "Guide to Your Investments." Mr. Hardy has a solid, common- sense attitude. This is no get-rich-quick book advocating high-risk, speculative investments that can also lose buckets of money.

In fact, the book is so comprehensive in its consideration of investment theories, possibilities, and facts that the new would-be investor many find his head spinning. Hardy does not offer a specific buy-this, buy-that formula. Rather, he gives good advice on the mechanics of investment in various markets and on how to acquire the detailed knowledge needed for wise investment. The book does include sample portfolios for purposes of illustration, not recommendation. In general, the book's careful, research-heavy approach may be safer for the wallet than some blind investment formulas.

Hardy has behind his book one of the nation's most sophisticated and largest market research and information-gathering organizations -- Dun & Bradstreet. I suppose it would be tough for such an organization to be completely negative on the stock market, since that market is so important to the firm's advisory business. Nonetheless, it is interesting that Hardy is so optimistic about standard investments in contrast with so many of today's popular doomsayers.

"More than at any time in modern memory," he writes, "investors should be of good cheer. For the 1980s, they have rewarding choices with securities: (1) sure, high yields of 12 percent for 20 years or more from well- rated bonds; (2) equally certain, and even higher, total returns -- interest plus appreciation to par at maturity -- from discount bonds; (3) potential profits, from modest dividends and substantial capital gains, of at least 14 percent from quality common stocks."

A less optimistic view of securities investment is offered in "How to Beat the Financial Squeeze" by William G. Flanagan. "Sooner or later -- if you haven't already -- you are going to get burned on Wall Street, even if you are not a very affluent cat," this columnist for the Wall Street Journal writes here. "With the number of lean and hungry salesmen for brokerage houses out beating the bushes, it's a good bet one will eventually get to you . . . judging by past history, it is more than likely that you will lose money."

Though that last assertion may be true on average for the stock market for several years in the 1970s, Colburn Hardy's book cites statistics that indicate it is not valid for much of the market's earlier history. And the market has done well in the last year or so.

In any case, the quote gives the flavor of Flanagan's approach; it is journalistic, full of slang, chatty, anecdotal, hard-nosed, perhaps a little smart-alecky. The book is wonderfully readable but has a grab-bag approach which jumps from topic to topic, as if compiled from expanded or reworked newspaper columns. Flanagan looks -- usually with good sense -- at debt and savings, securities, gold, house- buying, pension tax shelters, life insurance, a few frauds, and so on. He also presents a rather sympathetic look at gambling , offering some advice on this too.

Carl E. Andersen's "Seer or Sucker" is not so much a how-to book as one on investment philosophy. Andersen writes from over 30 years experience in the investment business, most recently with a large Boston mutual fund. The result is some excellent advice on how to avoid the perils of sharp investment practices and on how to beat today's high inflation rate.

His advice will prompt many readers to rethink carefully how they handle their money. For instance, he urges dumping cash- value life insurance for term insurance. He has excellent warnings about borrowing against the equity in your house for investment, purchasing fad stocks, or incautiously sinking money into collectibles. He has good tips on choosing mutual funds and investment advisers. And he provides a simple, brief explanation of "capital market theory."

Dr. Ira U. Cobleigh, author of "The Hidden Stock Market," seems to turn out investment books like a stuck Xerox machine. This is apparently his 19th book since 1951. In company with Bruce K. Dorfman, he wrote a somewhat better book in 1979 for Macmillan Publishing Company, "The Dowbeaters: How to Buy Stocks That Go Up" (New York. $8.95).

Both of these books are examples of the get-rich-quick variety of investment advice, which may be dangerous to your financial health. However, in "The Hidden Stock Market" Dr. Cobleigh does point to the fact that the stock of some of the small companies out there may rise rapidly for speculative as well as sound reasons. And he makes some suggestions about how to find these companies.

But without adequate research on the part of the reader into these relatively unknown firms, investment in their stocks can be a high-risk activity -- strictly not for widows and orphans. Even cheap stocks can plunge in value.

The Cobleigh books are not for the unsophisticated investor -- and perhaps not even for the investor who knows his way around.