THE NATION'S leading newspapers have made themselves into important adjuncts of the business of selling Watergate books, much the way television talk shows have lent themselves to the merchandising of self-improvement books. You already know from reading The Post and The New York Times and the weekly news magazines that you must go out and buy Haldeman's new book.

This urgent message has been conveyed in the size of the headlines, the breathless promises of the gossip items, the length and tone of those articles which debate the merits of Haldeman's "sensational revelations." People will go out and buy a book which draws excited front-page notices, a book which skillfully creates its own aura of intrigue and which sets the titans of the press to arguing among themselves over the ethical rules for marketing a scandal.

Watergate isthe most sucessfully merchandised scandal in the history of the republic - which proves once again the power of the press, even as it erodes its credibility. There is credit for everyone in the business, but newspapers have done more than their share to see that convicted felons become wealthy authors. H. R. Haldeman, who was so despised by the press originally, will be laughing all the way to the bank (though he cannot actually go to bank until he gets out of prison).

This merchandising process has one final step to it, this review, in which the careful reader is quietly informed, back in the book pages, that H. R. Haldeman's new book is, notwithstanding the frontpage headlines, the delicious gossip and controversy, a fraud. The review will have very little effect on sales, but it makes everyone feel clean.

The book is fraud. That is a terrible thing to say about anyone's book, but Haldeman's is fraudulent in terms of its own self-proclaimed virtues. The advertisements, drawing largely upon the hype from the newspaper, promise us a book studded with sensational revelations, a book of lasting historical value, and one which offers absorbing reading.

It is none of the above, in my judgement.

As one of the legions who spent nearly two years immersed in the complicated minutiae of Watergate, I could not find anything in this book which alters that story of criminal conspiracy in the White House, unless one is willing somehow to accept Haldeman's bilious speculations as fact. It seems to me a bit late to trade on half-baked speculations, especially from a man who worked so hard to conceal the facts. It is now almost five years since Haldeman went over the side, ample time for him to get the truth together in his own head.

Instead of new light, Haldeman is selling more shadows. Rumors, conspiracy theories, imagined conversations, midnight ruminations from his jail house cell. Every convict re-tries his case in prison and, little wonder, he is usually acquitted, once his imagination discovers the missing evidence which would have persuaded the jury or fingered the real culprits who should be sitting in his place. This is what Haldeman's book is about - jailhouse ruminations on what might have been. It is a honest with the facts as Haldeman was when he was serving President Nixon in the White House.

For historial purposes, it contributes onlu confusion. The book is a compendium of every prurient theory - none of them proved in fact. It asks the reader to indulge with H. R. the possibility that it was not the Nixon White House which was responsible for these crimes but someone else, the CIA or the Democratic Party itself or perhaps an evil virus in the air of Washington. H. R. offers these willfully, scattered through his jumbled narrative like glowworms of hope. But of course he cannot embrace them totally because he has no new facts to advance.

The publishing subsidiary of The New York Times , which asserts a reverence for historical documentation, has published a book without an index. It has three or four throat-clearing introductions, dedications and apologies from Haldeman, but no index. This indicates to me that the publisher doesn't expect the book to be on the library shelf when the important histories are written in future generations.

The last claim for the book - that it is good reading - seems to me the most strained. I don't know how many times people want to hear this story of Watergate, but H. R.'s version is among the least felicious - an often-told tale, badly told once more. It relies principally on old and familiar materials, the Ervin hearings on television (where Haldeman committed perjury), the White House tape transcripts (where the true nature of these men was so compellingly revealed) and even other previous Watergate books.

Yet Haldeman and his writer have chosen to assume such a dense knowledge of Watergate facts on the part of readers that I imagine his account will be virtually unreadable to anyone who doesn't know the story intimately.Indeed, the book delivers self-conscious crumbs, now and then, to those addicts whom Haldeman warmly addresses as "Watergate buffs." It sounds a little like those memoirs from aging film stars, trying to keep the fan clubs together.

If you are beginning to sense that this book made me mad. I confess it did. It revived that old kernel of anger which I thought was past, the widely shared outrage associated with that terrible passage of history, when Haldeman and his minions were offering the American people the most blatant, condescending lies to cover their peculiar behavior. The shredding of evidence, criminal bribes paid from secret slush funds, the eager manipulation of governmental machinery for personal political benefit.

Yes. Haldeman expresses regrets and second thoughts. He wishes they had done things differently. He wishes particularly that he had not been caught and sent to prison. But the operative tone of the book is catty and the mode is manipulative, much like the way the truth was used when Haldeman was in the White Huose.

Here for instance, is the depth of his contrition:

"Had Watergate been handled through the usual white House staff system, it would never have happened in the first place. And even if it happened, it would have been handled in such a way as to avoid the disaster that it eventually became."

Freely translated: if we responsible managers at the White House had been in charge of those crazies, we would never have let them do a burglary. Alternately, if they did a burglary, we would have done a better job of covering their tracks.

That sounds mildly plausible until one steps back and remembers that the burglary squad was assembled originally under aegis of Haldeman's vaunted "staff system." Liddy and his brothers did burglaries for the White House - has Haldeman forgotten? - before they were transferred to the campaign committee where they did more burglaries. The transfer was aouthorized by Halman. He sent them regular memos demanding better results. His files were loaded with their intelligence reports. These were among the first documents shredded afterwards.

So Haldeman is still stuck on the same contradition which made his testimony so hard to believe in the summer of '73. He wants friends and fans to believe that he really didn't know anything about these scandalous activities, a claim of innocence which competes with his boasts as an effectives manager. He is either dumb or he is a liar. The jury decided he was not dumb.

This is what is most irritating that Haldeman should proffer at this late date the same stale contradictions which was rejected in every forum. Apparently he expects the reader to reason innocently through his indulgent version and come out feeling that H. R. has been wronged, after all.

But wait. To be fair, there is something new and different from Haldeman. He has turned on his old master, as venomously as he turned on any of Nixon's enemies.

Haldeman, provoked by Nixon's appearances on television last year, decided to tell the awfull truth about him. I assume Nixon will feel free to reciprocate in his own memoirs.

The whole truth, according to Haldeman, is that Nixon was twisted, mean-spirited and sometimes dangerously obsessive in his private behavior.We already knew this. Haldeman adds a couple of bizarre anecdotes to the portrait.

H. R. goes further: he has concluded in his ruminations that it must have been Nixon who started it all, who ordered the burglary while his crackerjack "staff system" was looking the other way. I suppose some will find this titillating, but it is hardly a shocking speculation. Many of us assumed as much from the start, but nobody was ever able to prove it, not any of the scores of professional investigators.

Now here is the last cruel joke on Nixon: Haldeman doesn't prove it either. He simply offers, as his own malign theory, his personal conclusion that Nixon's the one.

To support this, H. R. offers and imagined conversation which might have taken place between Nixon and himself. But Haldeman isn't sure when. If it took place right after Watergate,this little "reconstructed" chat would certainly deepen Nixon's criminality. It would also contradict Haldeman's trial testimony when he promised before God to tell the truth. "I wonder," Haldeman says.

So may we all. Maybe the next bombshell memories will set the record straight, tell us the whole truth about those sordid years. We will be hearing next from Nixon and then from Henry kissinger and I feel sure those books will be sold hard in the news columns. Let the buyer beware.