Ronald Reagan now is being described by intimates as ready to campaign hard and early for the Republican presidential nomination in 1980.

While the former California governor has shied away from an announcement of candidacy that would require him to give up his lucrative radio commentary and newspaper column, the entourage that helped Reagan almost upset then-president Ford in 1976 is gearing up for a rematch.

Money is being raised. Some former aides have turned down otherwise attractive job offers outside the Reagan organization on grounds that they will be busy in the campaign by early 1979. Reagan's closest supporters say a decision has been made to run and that announcement of a new "citizens' committee" making this clear will be made no later than March of next year.

"If he isn't a candidate, I've never seen one," says Sen. Paul D. Laxalt (R-Nev.), chairman of the Reagan national campaign in 1976.

Laxalt, the national officeholder on whom Reagan depends most for counsel, says that he is "all out for Reagan," and predicted that an early announcement of candidacy will be made because the "obstacle of last time," a Republican incumbent president, does not exist.

Other Reagan loyalists say the same. Michael K. Deaver, president of the advertising firm that manages Reagan's business accounts, and Lyn Nofziger, who directs the Reagan-sponsored political action committee known as Citizens for the Republic, are basing their activities on the premise that Reagan will run.

"I expect him to run," says Deaver. "His planning today is geared toward an affirmative position."

Also anticipating a Reagan race is John P. Sears, the Washington attorney who managed Reagan's 1976 campaign.

"He's in a strong position" says Sears. "He's the only guy up there with a proven constituency and the ability to raise money."

On Gerald Ford's side of the political equation, there is considerable uncertainly about whether the former president will bw a candidate.

Ford tells everyone who asks him that he is undecided about running, and his friends and supporters take him at his word.

"At this point I think that Ford himself doesn't know what he'll do," says Stu Spencer, Ford's leading strategist in the 1976 campaign.

There are those in Ford's circle who believe he will be drawn into the race because of his acknowledged dislike for Reagan, if it appears that no other GOP candidate can beat him. The dislike is personal, not ideological, as Ford demonstrated when he welcomed the announced presidential candidacy of conservative Illinois Rep. Philip M. Crane.

However, intimates of Ford say that he is unlikely to run because of his family, which is deeply divided about whether he should do so.

Betty Ford's opposition to a further Ford candidacy is well-known. In addition, says a close friend of the family, the Ford children are divided, with Jack and Susan favoring a 1980 candidacy and Steve and Mike standing with their mother.

Ford has attempted to mollify this opposition, says one intimate, by emphasizing that he doesn't intend to slug it out in primaries with Reagan and other candidates. Republican politicians in California generally think that this position would make Ford either a noncandidate or a too-late candidate, since there will be an estimated 38 primaries in 1980.

Reagan's aides say that the former California governor is convinced that the winner will be decided in these primaries, and that he will start out as a frontrunner. It would be a new position for Reagan, who was a belated and indecisive candidate in 1968 and who faced an uphill challenge against an incumbent of his own party in 1976.

The Reagan people are comfortable with this prospective role, although they acknowledge that being the frontrunner has its dangers.

"Last time Ron was the David taking on Goliath," says Laxalt. "This time he'll be cast in the Goliath role, and there are a lot of Davids out there."

Publicly, Reagan and his supporters discount the importance of the age issue, which outsiders see as potentially telling even among voters who share Reagan's philosophy. Reagan, if elected, would be 70 six weeks after his nomination and 74 if he served a full term.

Reagan, who looks years younger than his age, has observed that the electorate is growing older, too. He believes that voters tend to judge a candidate by the way he looks and behaves rather than by chronological age.

But there is concern that an inadvertent action or misstep - a verbal stumble or a nodding away at a political banquet - would make it possible for Reagan opponents to successfully portray him as too old.

While the cast of the Reagan rerun is expected to be largely unchanged, there will be a change in roles for some of the players and probably a new director.

Laxalt said that Sears will not be the campaign manager in 1980, but will have a role in the Northeast and as a strategist if he wants one. Sears said he expects to be part of the campaign, but hasn't discussed any specifics with Reagan. Similarly, Nofziger's role has not been decided, though he will be part of the campaign.

Both Deaver and Laxalt said that a campaign manager has not yet been chosen and that Reagan has been sounding out various Republicans.

One of these is William Timmons, the effective manager of Ford's floor fight at the 1976 Republican National Convention, who met privately with Reagan last Monday. But no decision on a campaign manager for 1980 has been reached.