From her two-story office building out beyond the Capital Beltway in Vienna, Judy German commands a staff of 12 whose mission is to canvass the country, and find out what the federal government can't -- or won't -- tell the public: where it is hiding all its jobs.

German is more than willing to spread that word, twice a month in a little orange-colored newsletter that sells for $4 an issue. That publication, in an age of budget cuts and retroactive hiring freezes, has made her something of a fairy godmother to federal job seekers.

Call her a fairy godmother and she laughs. All the way to the bank.

Her prosaically named Federal Career Opportunities , one of a handful of private publications listing federal jobs, has become a hot property at federal libraries in Washington and government hiring offices around the county. The Office of Personnel Management, which puts a copy out on the counter of its main recruiting office here, has to tie the booklet in place with a steel chain.

"Sure I use it," says a federal program analyst curled up at a nearby library with a copy during his lunch hour. ". . . I like to know what's open."

Thanks to a meticulous, ongoing schedule of visits and telephone calls to federal agencies in Washington and around the country, German knows as much about where the federal government is hiring as the federal government. More, really, because the government is so big it doesn't keep track of it's job openings.

"It's not our job," says Steve Davis, a recruiting and information officer at the Office of Personnel Management. "There's nothing in OPM's budget for that. Many of the people who use a newsletter like that already have federal jobs and are looking for ways to move up. The taxpayer doesn't want to finance career development for federal employes.

German, who managed to list more than 3,000 openings in the midst of the recent Reagan hiring freeze, agrees.

Like an Ann Landers of the federal bureaucracry, German peppers her newsletter with blunt advice to the ambitious and solace for the frustrated. "The key point to remember," she wrote at the end of the Reagan freeze, "is that the across-the-board hiring freeze is now lifted. We expect to see continued confusion among the non-defense agencies for the next several weeks . . . Meanwhile, job hunting is best in the Department of Defense, where recruiting is being conducted on a business as usual basis."

If the federal government is shrinking, you wouldn't know it from German's business. In seven years her newsletter and company, Federal Research Service Inc., have evolved from a small hand-cranked operation in the basement of her Northern Virginia home into what she concedes in a million-dollar operation, complete with accountants, government liaison workers, and a roomful of computers.

Subscriptions have climbed from 22 to 8,000, including 11 that go to OPM, the agency that's charged with managing the federal bureaucracy, and one that goes to a staffing specialist aboard the aircraft carrier John F. Kennedy.

"I was surprised to find that a lot of people look at this thing," says Mitch Guthaim, a civilian personnel recruiting specialist at Warner Robins Air Force Base in Georgia. "We've had a large response from our listings, and we've hired people, too. We advertise in trade publications, but that costs us a lot of money, and this is free."

The listings may be plentiful, but reading them is like, well, reaing a government personnel manual. Consider, for example, the following listing: "Electronics engineer (Robins Air Force Base) (181) (Design, modification, debugging, validation and certification of automatic digital test equipment . . ."

The number in parenthesis is important and it isn't a secret code. "It means we need 181 electronics engineers," says Guthaim. "And we need 'em yesterday."

Ronald Reagan's hiring freeze may have shocked some job hunters, but Judy German has been around long enough to know better. "People forget," she says "but Jimmy Carter set a record with three hiring freezes. One of the differences is that he didn't manage to do it with the same kind of fanfare."

Her newsletter's sales "did a lot of peaking and valleying during the Carter years," says German. The Reagan victory, and freeze, predictably, produced a short-lived death-valley, too.

German says it didn't have to be that way. "People don't understand the difference between a hiring freeze and a recruiting freeze. During a hiring freeze the government is still recruiting. The agencies can't make offers, but they keep right on looking. That way, when the freeze is lifted, they don't lose any time."

At least half of the newsletter's subscribers, German figures, already have federal jobs, and are looking for transfers of promotions. The rest are standing on the outside looking in, eager for federal employment but often are unfamiliar with how to go about getting it.

Success has brought imitators. In the last few years she's taken two of them to court for copyright infringement, and won. The cases were settled out of court and today her "Federal Career Opportunities" is virtually unchallenged in the field.

"This one is better," said Donald Winslow, a District employe who said he left a federal job for the city government in a moment of folly and is now trying to get back on the federal rolls. "It has more listings, and they give you more information about the job. No point in sending out a 171 [the basic federal job application form] unless you know what you're applying for."

Winslow stood as he copied listings into a small spiral notebook. The woman next to him, reading from another copy, was standing, too. They had no choice. At the Federal Job Information Center on Virginia Avenue they keep the newsletter tethered to the wall with a short steel chain.

"Oh yes, we've got to do that," said a clerk matter of factly. "You wouldn't believe how many people try to walk off with it."

Judy German never expected to be a publishing tycoon. She came to Washington in 1962 from Michigan, found an apartment in Northern Virginia and a secretarial job with the Navy Department. By the early 1970s she was working as an employment manager for a defense research company.

When the company lost some key Navy contracts, German was put in charge of finding federal jobs for PhDs who were being let go. "I figured I'd just match up my people with the vacanies on the government list." But of course, there wasn't a list.

The Office of Personnel Management, which is the new name for the old Civil Service Commission, is about as close to a central employment agency as the federal government gets. Except that it's not.

Instead, it works a little like a supermarket, keeping lists of qualified candidates on hand for when agencies with vacancies come shopping. OPM's Federal Job Information Center is a clearinghouse of job information. It is also a mecca for those who want to get a government job.

OPM recruiting specialists are aware of the newsletter's appeal, but they do not see it as everyman's oneway ticket to success. "A newsletter like that is a good tool for an agressive job seeker," say the OPM's Steve Davis.

And there are a lot of people who are seeking federal jobs these days. According to the Davis, last year more than 7 million people inquired about federal jobs at OPM branches around the country. Compare that number to the 111,512, the number of actual hires, and you've got a lot of people eager to find out what went wrong and try again.

German understands that now. She didn't in 1974, when she was just starting out. "In the beginning I thought 'They must have a secret they're keeping from me.' I was going from agency to agency and making phone calls all day long. It took forever. It was unbelievable that the only way to find out what was open was to run down to the next building at lunch hour, and hope that the secretary there had updated the bulletin board before she went to lunch."

It wasn't long before German decided that if she could look for jobs for seven people, she could just as easily find jobs for 700, "or 7,000, for that matter."

In addition to the newsletter, German's company holds seminars, where for $95 they'll teach a job prospect how to fill out a sure-fire Form No. 171.3 And Federal Research Service offers courses in career development, as well.

Despite the OPM's admonition against taxpayers financing federal job counseling German has contracts with at least three federal agencies to teach the same things to government employes, on government time.

If government agencies have their own staffing specialists and employe development specialists, what do they need German for?

"We focus on informing the employe that you are responsible for your own destiny," says German. "We try to let the employe know that the agency doesn't owe you anything in terms of advancement. We teach them to help themselves, let them know that it's not the agency's responsibility to haul you out of bed.

"And I guess the bottom line is that sometimes it's better to hear that from someone you're not working for."