I currently own the Viking hardcover edition of these transcripts, but read this paperback edition originally.
The whole Watergate affair started with the break-in to Daniel Ellsberg's (the former RAND Corporation employee who leaked the Pentagon Papers) psychiatrist's office by the White House 'Plumbers' (they fixed leaks). This occurred, as I recall, during the 1972 election campaign, but, being but the tip of an iceberg, it had no real effect on the outcome, Richard M. Nixon's reelection.
More came out, however, in dribbles mostly, during 1973/74, but it was probably Nixon's overt obstructions of justice that did him in--that and the enemies he'd made in the Establishment. In any case, the revelations of 'dirty tricks' apparently engineered by the White House made for exciting reading for months and months. I became, for the first and only time in my life, a regular reader of both Time and Newsweek magazines.
After impeachment proceedings began and Nixon, anticipating eventual conviction, resigned, these transcripts made by hidden recorders in the Oval Office, central to the case against the President, came out. One is not impressed by the President. He seems so ordinary--and not as an ordinary, nice guy, but as a vindictive, scheming son-of-a-bitch.