On the fifth floor of the Lord Baltimore Hotel, behind a desk in the middle of a dank and narrow hallway, sat the receptionist for candidate Harry R. Hughes. She had been answering the telephone for the past six hours, time and again trying to explain to callers why they had been unable to speak personally with the Democratic nominee for Maryland governor.

-As you know this was a big shock to everyone," the receptionist could be heard telling a woman from Anne Arundel County. "Suddenly, everyone and his brother wants to speak to Mr. Hughes. Several senators haven't even been able to speak with him yet. It's not that he doesn't want to, but we're still trying to sort everything out."

This was last Thursday afternoon, a full 10 days after Hughes had surprised Maryland's political world by winning the Democratic primary. It was apparent that the stunned still included Hughes' own campaign staff. Some of the most elementary aspects of a political operation were just now being worked out.

In an room, technicians could be seen installing a new and expanded telephone system to replace the two telephones that sufficed during the primary. In another room Joseph Coale, the young campaign coordinator, fiddled with a schedule that was still being drawn up on a day-to-day basis. Nearby was Mike Canning, the other top aide, combing through a stack of more than 300 telephone messages. And behind the door of Room 502 were Harry Roe Hughes and his running mate for lieutenant governor, Samuel W. Bogley.

Bogley, a Prince George's County Council member, emerged from the conference with a smile on his face. "You know," he said, when asked what the smile was about, "I'm just starting to realize that I'm part of something really big."

Unlike Bogley and many of the Hughes people, J. Glenn Beall realized he was part of something really big several weeks ago. Assuming, correctly, that he would have little trouble winning the Republican nomination, the former U.S. senator began preparing for the general election campaign long before the primary race ended.

His campaign schedule had been mapped out weeks in advance. There was no need for Beall to reshape his working quarters or his staff. His television commercials were ready two weeks ago and went on the air the day after the primary.

One of the few things Beall did not prepare for ahead of time was Harry Hughes. He has assumed, as had most people, that the Democratic nominee would be Acting Gov. Blair Lee III. Beall has adjusted to his surprise opponent quickly, however, using the same theme that he had planned for a campaign against Lee.

"Some of my opponent's supporters would lead people to believe that he is a new face on the Maryland political scene and that he represents a clean break with the past." Beall told a gathering of the Maryland Federation of Republican Women last Friday.

"Well, he may be a nice guy, but he is certainly not a new guy. For 24 years my opponent has been a part of the state government. He has been in the forefront of those in political control of the state who have given us one of the most rapidly growing governments in the country and an intolerably high per capita tax load."

Beall is expected to carry the message of lower taxes and reduced government throughout the campaign, appealing to the conservative, antitax mood of the electorate. The Republican National Committee, which has made tax cuts a party rallying cry this year, is expected to help Beall by sending in several prominent GOP leaders to campaign for him.

"Despite all the tax revolt talk, it was not really a factor in the Democratic primary," said Maryland Senate President Steny H. Hoyer, who ran and lost as Lee's lieutenant governor candidate. "Harry's going to have to deal with that now. And he's also going to have an opponent really zeroing in on him. In the primary, Hughes kind of stood aside as the rest of us (Lee. Theodore G. Venetoulis and Walter S. Orlinsky) tore one another apart. I think it's going to be a tough fight for Harry."

Hughes and his aides plan to say the same things in the race against Beall as they did in the primary.

"Harry's intention is not to change his message," said Canning. "he still will run as an independent - owing nobody anything, not making any deals or promises, not adjusting his positions. He believes the state pension system must be reformed, for instance, and he's not going to change that just to please the teachers. And he believes that collective bargaining for state employes should not bind the legislature to give employes a predetermined salary increase, and he's not going to change that just to please labor."

In the primary, Hughes campaigned and won without the support of the AFL-CIO, the teachers' union, the established political organizations in Baltimore and Prince George's County and the black leadership in the urban centers. As the Democratic nominee, however, he must form some sort of working relationship, or a least not antagonize, these traditional elements of his party.

There was some behind-the-scenes grumbling during the week after the primary that Hughes was still trying "to go it alone," as one labor leader said. One union official said he had to work through Stephen Sachs, the Democratic candidate for attorney general, to get an audience with Hughes. Dominic Mimi DiPietro, one of the last old-fashioned political bosses in Baltimore, said he had yet to be contacted by the new party leader.

"I haven't been told a damn thing yet," said DiPietro. "If he don't want me, how can I take him? I just stay home that day (election day) and go to sleep or take my wife on a vacation to Florida."

Hughes has made it clear that he will not provide DiPietro or any other political club with "walk-around" money to pass out sample ballots and get out the vote on election day. He will, however, provide money for the local sample ballots and brochures. Whether that will satisfy some of the old-line party leaders in Baltimore is uncertain.

"Walk-around money creates the feeling of being part of a family," said one political leader. "If Hughes doesn't come in with it, he's in trouble."

Most of the old-line Democrats in Baltimore say publicly, however, that they expect to get along with Hughes. "They might not want it that way (no election day money)," said state Sen. Harry McGuirk, a Hughes critic in the primary who is now angling to replace Hoyer as Senate president. "But eventually they'll all sit down and say we want to be with a winner. If you're not with a winner, you can't request anything for yourself or your district."

Beall attracted the last-minute support of several Democratic clubs in his 1970 U.S. Senate race against Joseph Tydings by supplying them with about $45,000 on election day. It was at least a minor factor in his victory that year. This time, however, Beall says he will stay out of the "walk-around" money game.

"I established the practice of not using it in 1976 (when he lost to Paul Sarbanes)," Beall said in a recent interview. "I think you should do things with volunteer help and not spend money on getting people to work for you."

Beall still plans to spend most of his time courting Democratic voters - a necessity in a state where the Democrats hold a better than 2-to-1 edge in registration. He may be helped in that effort by strong Republican candidates in the state's two largest counties - Baltimore County and Prince George's COunty.

Baltimore County was Hughes' most fertile territory in the Democratic primary. Most observers say the 40,000 vote margin he attracted there won the state for him. Hughes was bolstered then, however, by a massive negative vote against County Executive Venetoulis, who, of course, will not be a factor in the general election. The Republican candidate for county executive there, Eugene Kibbe, is said to have a good shot at winning in November. The Republican strength there already is demonstrated by the presence of three GOP state senators and seven delegates.

In Prince George's County, where Democrats hold a 3-to-1 registration edge, former Republican member of Congress Lawrence J. Hogan is waging a strong campaign against Democratic incumbent County Executive Winfield M. Kelly Jr. Beall is hoping that Hogan's popularity will help the top of the ticket.

The lieutenant governor candidates, Bogley and Republican Aris Allen, are expected to play major roles in the courtship to two important constituencies - Catholics and blacks. Bogley, a strong antiabortionist, was the only major Democratic candidate to receive the endorsement of Catholic newspapers and parishes during the primary. Several parishes passed out Hughes-Bogley literature on the Sunday before the election. Hughes and Bogley happen to disagree on the abortion issue, with Hughes supporting state-funded abortions in certain circumstances.

Allen, a physician from Annapolis, is the first black lieutenant governor candidate in Maryland history. He may help Beall cut into the traditionally heavy black Democratic vote in Baltimore. Said state Sen. Clarence M. Mitchell III: "Unless Hughes makes the kinds of commitments that would serve to offset the symbolism of a black being in the No. 2 position, we're going to have difficulty selling him."

Hughes has issued a seven-point pledge to black leaders, promising, among other things, to appoint at least one black and one woman to the cabinet and give them more positions on state boards and commissions.

Bogley and Allen are both modest men who have sometimes startled their running mates by their self-deprecating statements. Bogley, in the week after the primary, was quoted several times as questioning his own abilities to lead the state should anything happen to Hughes. And Allen, at the Republican women's session in Gaithersburg, opened his address by saying, "I want to address the question: As a black man, are you qualified for the office to which you aspire?"

Beall said later, "I think he should have said, 'this is why I'm qualified as a human being to be lieutenant governor' - and that's what he is."