President-elect Ronald Reagan yesterday named retired general Alexander M. Haig Jr. as secretary of state, an already controversial appointment, and chose Raymond J. Donovan, a New Jersey contractor unknown to most labor leaders, as secretary of labor. a

The secretary of state nomination ended weeks of speculation over whether Reagan would name Haig after questions were raised about his role in the final stages of the Watergate affair, when the former four-star general served as Richard M. Nixon's chief of staff.

But the controversy over Haig is far from over, as the warning signals from Capitol Hill made clear. Democrats on the Senate Foreign Relations Committee, which will hold confirmation hearings on the nomination, have retained Terry Lenzner, assistant chief counsel of the old Senate Watergate Committee, as a consultant on the nomination, it was learned.

"This is a nomination that should not have been made," said Sen. Alan Cranston of California, assistant Senate Democratic leader in the outgoing Congress and a member of the Foreign Relations Committee.

He said the nomination would provoke serious controversy, adding that he and a number of other senators had questions about Haig's role in the Vietnam war, Watergate and the pardon granted to former president Nixon by Gerald R. Ford.

"These must and will be fully explored," said Cranston.

The nominations represented a clear turn to the right in the Cabinet-selection process. The first eight appointees to Cabinet or Cabinet or Cabinet-level positions, named last Thursday, composed a mainstream Republican group that pleased party moderates but raised concern among Reagan's conservative backers.

Both Haig and Donovan were supported by conservatives. In addition, it was learned that the Reagan high command has picked Richard Richards, a conservative former GOP chairman from Utah, to head the Republican National Committee.

A Senate fight over Haig's nomination appeared increasingly likely last night. Well-placed Senate sources said both Democratic leaders, Robert C. Byrd (D-W.Va.) and Cranston are eager to give Haig's nomination close scrutiny.

According to an aide to Sen. Claiborne Pell (D-R.I.), who will be the ranking Democrat on Foreign Relations n the new Congress, counsel Lenzner will be a consultant to the committee's Democratic minority staff will be detailed to work for him, and have already been assigned areas of inquiry.

The principal areas of Haig's past that Senate Democrats want to investigate, sources said, include the following:

Haig's role in the first Nixon administration's program of clandestine wiretaps of government officials and journalists. Haig is cited in FBI records as the man who requested 12 of the 17 wiretaps.

When this program was under way in 1969 and 1970 Haig acted as a go-between for Henry A. Kissinger in the White House and J. Edgar Hoover at the FBI. He was the first White House official to read many of the transcripts of conversations picked up by the taps.

These wiretaps were the basis for the second count in the impeachment indictment of Nixon approved in 1974 by the House Judiciary Committee.

Haig's role in the Nixon administration's conduct of the Vietnam war, operations in Cambodia and the Vietnam peace negotiations. During the years he worked for Kissinger on the National Security Council staff, Haig played an active role in the administration's Indochina policies. He was an ardent advocate of the Christmas bombing of Hanoi in 1972, and Cranston intends to explore the relevance of Haig's past policy recommendations to his suitability of secretary of state, aides said.

Haig's relations with the Watergate special prosecutors and congressional committees that investigated Watergate in 1973-74. The Democrats on Foreign Relations want to detrmine whether Haig cooperated with those investigations or helped Nixon try to frustrate them, one Senate source said.

Haig's role as in intermediary between Nixon his successor, Ford, at the time of Nixon's resignation. Ford has recorded in his memoirs that Haig suggested that Nixon could resign the presidency and Ford could pardon him for any and all crimes (which is what happened). Ford's key aides thought this was an improper conversation. Ford and Haig have both denied there was any "deal" between them.

Senate Democrats will be looking into many other areas as well, sources said. They will have to hurry, however, as the Foreign Relations Committee's new chairman, Charles H. Percy (R.Ill.), tentatively plans to begin confirmation hearings for Haig on Jan. 9.

The Cabinet announcements were made in an atmosphere devoid of fanfare or ceremony. Neither the president-elect, who is on a working vacation in California, nor the two nominees took part, supposedly because Haig was in bed with the flu.

Transition press spokesman James Brady simply read brief statement from Reagan, in which the president-elect announced the names and praised both men as "individuals with proven records of success at the highest level."

Reagan, cornered briefly as he entered his barbershop in Beverly Hills, said he was confident the Senate would confirm Haig. "I know that the Senate will look at everyone that I appoint," he said. "But there's nothing uninvented that can be brought up against him. I think he is the man for the job."

Haig, 56, was in bed with a 102-degree fever yesterday at his home in Farmington, Conn., near Hartford, where he is president of United Technologies Corp.

Despite his reported illness, Haig met reporters briefly on the doorstep of his home. Asked about the expected opposition to his nomination due largely to his activities in the Nixon administration, he said, "Sometimes, I feel like it's Halloween, there are so many bones rattling around." But, added, "I'm ready to set the record straight. I'm optimistic. Why shouldn't I be? I know what my record is."

Donovan, by contrast, is an unknown quantity, barely familiar to labor leaders of Reagan. However, he was one of Reagan's most effective fund-raisers and served as Reagan's New Jersey state campaign chairman.

Donovan, 50, has never run for public office, nor has he held appointed political office. He is executive vice president of Schiavone Construction Co. of Secaucus, N.J., a firm that specializes in highway and tunnel construction.

During his years as a student at Notre Dame Seminary in New Orleans, from which he was graduated with a degree in philosophy, Donovan was a member of the Ballantine Brewery Workers Union and the Electrical Workers Union. Since then, his contracts with organized labor have been on the management side.

He is highly regarded, however, by officials of the Teamsters, Operating Engineers and Laborers unions in New Jersey and New York. And he reportedly once told Reagan flatly that if he wanted the presidency he had to appeal to blue-collar workers.