By Megan Lane BBC News Online Magazine

What most will want to read about

The New York Times review of Bill Clinton's hotly anticipated autobiography could no doubt be applied to many a political memoir.

For reviewer Michiko Kakutani, the 900-plus pages of My Life is "part policy primer, part 12-step confessional, part stump speech and part presidential archive". Rather than write for the reader, she says the ex-president seems set on recording his side for posterity.

Other reviews have been more favourable, but the common consensus is that the author is prone to undisciplined ramblings.

But isn't it expecting a little too much of a career politician that he be a literary whiz to boot? Iain Dale, the founder of Politico's bookshop and himself a Tory hopeful, says the two need not be mutually exclusive.

"John Major's autobiography is one of the better political memoirs of the past few years. It was well-written, self-deprecating and honest - although he didn't mention Mrs Currie [Tory MP Edwina Currie, with whom he had an affair]."

The pair had an affair in the 1980s

Instead it was she who came clean about their four-year dalliance when her diaries were published in 2002.

Nor is it surprising that a politician might give a one-sided account. "It's a rare chance to put on the record their side of what they did. The best strike a balance between what some might consider to be the dull stuff of the job and the more exciting bits."

For this reason he rates Margaret Thatcher's second volume of memoirs, which covers up to 1979; and Robin Cook's The Point of Departure, an account of the run-up to the Iraq invasion, which sets out his motives for resigning from the Cabinet over the war.

Churchill shed light on his times

While the musings of notable figures such as Winston Churchill can greatly add to our knowledge of their times, political author Michael Dobbs says the best political memoirs are not autobiographies, but diaries written whilst in power.

"The greatest contributions to really understanding a particular type of political life are the diaries written by people like 'Chips' Channon and, more recently, Alan Clark.

"A diary captures the passion, the pressures and the pain that goes into political decision-making and political life in a way that autobiographies rarely do. They try to smooth out the rough bumps - but it's the rough bumps that are the most compelling, and tell us most about how politics works."

Dull read

What makes for a poor political memoir is one which reveals little new about the writer and their time in power. The late Ronald Reagan was guilty of this, Mr Dale says; as was the Tory MP Michael Heseltine and Mr Clinton's wife.

CLINTON ON PANORAMA Clinton The Interview

"Hillary Clinton's book was dreadful - why did anyone buy it? It was badly written, and didn't say anything at all that we didn't already know."

What readers want is names named, juicy titbits revealed and motives laid bare, as in the memoirs of two former Downing St insiders, policy advisor Bernard Donoughue and press secretary Joe Haines.

Both had numerous revelatory moments: that Mr Donoughue had been abused as a child; that Harold Wilson's doctor had suggested that the then PM's personal secretary Marcia Falkender should be killed. "They could afford to be less discreet as they're lesser known," Mr Dale says.

What most readers will judge Bill Clinton's book on is how he handles his affair with Monica Lewinsky.

"I haven't read it yet, but it sounds as if he does a better job than [former Tory Party chairman] Cecil Parkinson, who spent just three paragraphs on his mistress Sara Keays, with whom he had a child."

So what's the test of whether a political memoir is any good? "If you get to the end of the book and don't know anything new about the author, then the book has failed."