Last summer Rose Thorman left her GS12 job as women's program manager at the Bureau of Mines and decided to explore a new career. She enrolled in a candidates' school and spent three days on Capitol Hill learning about telephone banks, direct mail and how to get money from political action committees.

Today Thorman, who says 1982 is "the year of the woman candidate," is just that. Although she has never sought or held elected office, the 56-year-old Arlingtonian is running for Congress in Northern Virginia's June 8 Democratic primary.

She is not the only long-shot candidate in the race. Edward (Ted) McLaughlin, a McLean media consultant who has worked in several of the Kennedy family's campaigns, is also trying to capture the nomination and unseat incumbent Republican Rep. Frank Wolf. "All my life I've dreamed of running for office," says the 51-year-old McLaughlin.

Thorman's new career and McLaughlin's lifelong dream face the same formidable obstacle: Ira M. Lechner. A Washington labor lawyer and former state delegate from Arlington, Lechner, 48, is widely regarded as the front-runner in the race.

The primary is expected to attract relatively few of the 10th Congressional District's 255,000 voters. Most of those who do vote are likely to be party activists who know Lechner or at least recognize his name.

"Who are these people? Where have they been?" demands Loudoun County Supervisor Betty Tatum, echoing the sentiments of many Democratic workers toward Thorman and McLaughlin. "There are a certain amount of dues to be paid before running for an office of that magnitude. I think Rose is an attractive candidate, but I wish she'd run for something else.

"Just because you're a woman, doesn't mean other women are going to support you," said Tatum. Indeed, both the National Organization of Women and the National Women's Political Caucus have endorsed Lechner.

Even so Thorman and McLaughlin represent a new breed of suburban candidate, schooled in the new technology of campaigning but untested in the crucible of grass-roots politics. Neither candidate has the kind of local political base painstakingly constructed after years of work in other peoples' campaigns.

All three candidates agree on virtually everything. They favor a nuclear freeze, oppose the Reagan administration's budget cuts, and deplore the policies that have cost many federal employes their jobs.

Thorman has spent much of her campaign talking about the administration's RIFs of federal workers, which she called "the most vicious destruction of human beings that this country has ever seen." McLaughlin has focused on the cutbacks in education programs, saying Reagan has produced "the most anti-education administration in history."

Untroubled by any issues that differentiate them from Lechner, Thomas and McLaughlin have forged ahead on their campaigns. Thorman, wife of an international trade lawyer, rejects the charge that she is a political neophyte. "That's a lot of nonsense," she says angrily, noting that she was a member of the Arlington Democratic Committee from 1967 to 1972. "Working in local politics is just one way of paying dues. The other way to run is to gain expertise. I belong in national level politics; it's where I'm happiest working.

McLaughlin, a beefy, ruddy faced man who looks and sounds like a Boston politician, concedes his underdog status. "It doesn't worry me that the activists don't know my name. I don't think much of the Democratic organization here anyway."

Thorman's supporters include old friends and some people whom Lechner has alienated in his two previous races for Virginia lieutenant governor. They include Fred Berghoefer, former Arlington party chairman, and Virginia Highway Commissioner T. Eugene Smith, an old acquaintance, who gave her $500 but rates her chances as "very, very small."

Thorman, whose campaign buttons saying "Rose Is A Rose In Congress," has raised about $30,000, all but $5,000 of which is her own money and all but $10,000 of which she has plunged into radio commercials.

Patterned after the "Sam and Janet Evening" spots for the defunct Washington Star, Thorman's ads feature a "Burt" and "Rose" having "their nightly political debate in the kitchen of their modest Arlington home." A sample:

"BURT: Listen, Rose, we've been getting some rough calls down at the campaign headquarters.

ROSE: From who?

BURT: The Reagan people, I guess. They don't like what you've been saying about federal employes.

ROSE: Tell 'em they've got the wrong number. I was a federal employe for eight years and I think it's disgraceful the way Reagan is throwing career public servants out in the street . . . .Tell 'em to reach out and touch someone else."

McLaughlin, whose wife was a staffer with the Senate Foreign Relations Committee, says he is the most qualified candidate. "I know the Hill and I'm comfortable there," said McLaughlin, who sports a silver PT-109 tie clasp and frequently compares himself with the late John F. Kennedy, for whom he worked in Alabama in 1960. "Everybody said John Kennedy couldn't win, too.

"There's hardly any part of a campaign I don't understand," said McLaughlin, who also worked in the campaigns of the late Robert F. Kennedy, Sen. Edward M. Kennedy and former Sen. Birch Bayh.

While McLaughlin says he is "better connected" than the other candidates, he currently trails his opponents in fund-raising. He says he has raised $15,000, of which about $10,000 is his own money.

McLaughlin says he's confident of raising more money, mostly through direct mail. "Mail produces the best voter recognition there is," said McLaughlin. "After my mailing more people will know me than the other two.

"Ira's name recognition is good among the party activists, but a lot of it is negative," he said. "Obviously I'm confident of victory. I've always been confident."

Some party activists say that confidence may be misplaced. "I don't see him around the district or hear anything out of his campaign and I don't know anyone who's supporting him," said Arlington Democratic chairman Sharon Davis.

"I don't question the man or his sincerity," said Fairfax Board Vice Chairman Martha Pennino, who couldn't remember McLaughlin's name. "But there is absolutely no question in my mind that Ira will walk away with the primary. After all, you don't run for office without a constituency."