You're planning a move and want to compare the cost of living for a family of four in several U.S. cities. You head the Jaycees and need to know the status of a federal bill affecting local business. Your parents have high blood pressure and you'd like to learn how to minimize your chances of getting it.

According to research expert Leila Kight the answers to these -- and nearly any other question you can pose -- is for Washingtonians just a phone call away. (For the above: Dial the Labor Department's inquiries office at 523-1239, the House Bill Status Office at 225-1772, the High Blood Pressure Information Center at 652-7700.)

"Washington is a goldmine of information," says the 33-year-old president of Washington Researchers, a five-year-old company that specializes in tapping "the world's largest concentration of expertise and documentation -- Washington, D.C."

Her staff of 20 "info-maniacs" has researched topics ranging from abrasives to zinc. They've uncovered "everything there is to know about eggplants," investigated the status of eavesdropping legislation and researched the marketability of rubber-soled shoes in Eastern Europe.

"The information is usually somewhere in the federal government," Kight says. "The problem most people have is that they don't know how to find it. They make 10 calls, get transferred around and still don't get the right person. So they become frustrated and give up."

But it doesn't take a degree in library science to learn how to hit the information jackpot, claims Kight, whose firm has never hired a librarian as a researcher.

"We have a former French pastry chef and an ex-seminarian. We look for people who make others want to talk to them and aren't intimidated by getting into a new topic every day.

"Sometimes you're better off if you're not a hotshot specialist. Then it's too easy to know how hard it might be to find something. Ignorance is bliss in a lot of research projects."

Kight and her then-husband Matthew Lesko started Washington Researchers in 1975 as a "phone-and-desk-in-the-bedroom" operation. Today it is a more than $1 million-a-year business that has served around 500 research clients: mostly Fortune 500 companies or agencies that service major corporations and can afford the $75-an-hour, $375 minimum fee.

Knight attributes their success to two factors: "We're very good at what we do. And the demand for information has increased. There's such an explosion of information these days. People know they've got to be smarter to survive."

To satisfy the hundreds of people who call "asking how to find this, or where to look for that" they hold Washington Information Seminars several times a year.

The day-long sessions include information tips on Capitol Hill, the Library of Congress, trade association, think tanks and about a dozen federal agencies. The $195 fee includes a name-and-phone-number-packed Washington Information Workbook, a Researcher's Guide to Washington and a Federal Telephone Directory.

"The researcher's rule of thumb is to find an expert on the topic," Kight told the 100-plus participants (including a network news bureau chief, a bank executive and a soup-marketing specialist) at last week's session at the Four Seasons hotel.

"It's often the career Civil Service bureaucrat who'll know the answers. If you aim too low the person won't have enough information or authority to help. If you aim too high, it's likely to be a political appointee who is in and out too quickly to build up a base of information.

"At the workhorse level they know the answers. And if you're nice enough they don't mind takig the time to help you. A lot of mid-level bureaucrats get little recognition and may enjoy your interest in their expertise."

But, she cautions, you'll rarely get the right person on your first call. "Expect to make at least three or four calls -- or as many as 10 -- until you hit. When you expect that, it isn't so frustrating."

Once you locate an expert, your questioning technique can make the difference between an angry, fruitless exchange and winding up with a list of contacts and a stack of relevant documents sent to your home.

"Interviewing's an art," says Kight, who offered these "you-can-catch-more-flies-with-honey-then-vinegar" interviewing tips:

Make a positive first impression. "Your greeting and initial comments should be alive and cheery -- but not obnoxious. Give the person the feeling that yours isn't going to be another annoying call, but a bright spot in an ordinarily dull day."

Be open. "Let them know what you're after and why. If you are deceitful in explaining your needs or motives, this will eventually be detected and cause your source to be wary of providing information."

Consider the mind-set of the person you're talking to. "You'd phrase things differently to an oil-company spokesperson than to an environmental specialist." Don't misrepresent yourself; just be sensitive. a

Be respectful. "It's disastrous to tell a government employe that you're his boss since you pay taxes, so you deserve this or that. Never bully."

Be optimistic. "Exuding confidence will encourage your sources to stretch their minds to see the various ways they could help. If you say, 'You don't have any information, do you?' its easy for your source to saysay 'no, we don't.'"

Don't be a "gimmie." "A 'gimmie' is demanding and has no consideration for the other person's feelings. Let them know you realize you're taking their time and show appreciation."

Never overstate your knowledge. "People don't mind your being ignorant and may help you more. If you don't pretend expertise you're less likely to miss a lead or skip something important."

Remember the power of praise. "A well-placed compliment about the person's expertise or insight will come back to you a hundred times."

Ask for contacts. Chances are your source will know other places to look or sources of information. When you call these people, use your source's name to "warm up" a "cold contact."

Send thank-you notes. A handwritten note to particularly helpful people "will go a long way toward insuring that your source will be cooperative in the future."

Be persistent and patient. "Accepting a 'no' is easy, but not creative. You may have to ask your question several different ways to get an answer. If one person won't give you a document, the person in the next office might. At the very least ask the person for leads or suggestions of other places to try."