John Dean, self-styled ''snitch'' of the Watergate cover-up, has written a sequel to ''Blind Ambition.'' Much of the publicity has concerned his speculation that Deep Throat - the mysterious informant of Washington Post reporter Robert Woodward - must have been none other than Alexander Haig.
But Dean's attempt to track down Deep Throat is just one component of these memoirs, which also recount his efforts to come to grips with himself and embark on a new career after his release from prison. A few high points: Dean's stint at the 1976 Republican convention as a reporter for Rolling Stone; his conversations with scandalous Capitol Hill ''secretary'' Elizabeth Ray; the day he saw a side of Walter Cronkite he ''never would have thought existed.''
Evaluating the first draft of his earlier book, Dean says: ''At times I was clearly pouring ashes on myself, and at other times I was totally self-serving.'' To some extent, the same is true in ''Lost Honor.'' Still, I found myself returning to his narrative when I should have been doing other things - always a sign of readability.