Yet when it comes to her own life, talk-show queen Oprah Winfrey is anything but generous.

When talk-show megastar Oprah Winfrey lands in Australia next month, tucked away in her designer luggage will be more than her favourite Christian Louboutins.

Lumping along with the world's most influential celebrity will be the emotional baggage from one very bumpy year.

Oprah Gail Winfrey has a global reach of millions. She has been named by CNN and Time magazine as the world's most powerful woman, and as of this year Forbes magazine places her at No. 3 on its most powerful women list. At 56, she is the world's richest self-made black woman, having amassed $2.74 billion.

But this year the much-loved mogul learned first-hand the lesson spruiked by so many of her self-help gurus: you can't control everything, no matter how hard you try.

For starters, there was the myth-busting book, Living Oprah My One Year Experiment to Walk the Walk of the Queen Talk, by New York Oprah tragic Robyn Okrant.

In what began as a blog-as-artistic statement but became an online sensation, the yoga teacher and artist strove for 12 months to achieve Oprah's trademarked catchphrase: "Live your best life."

But in the book she never intended to write, but was persuaded to publish, Okrant found applying Oprah's every physical and spiritual guideline from a year's worth of shows to be costly, stressful and, eventually, exhausting.

Instead of delivering Winfrey's mission statement, to "uplift, encourage and empower" women, Okrant declared that "living Oprah" set many up for disappointment.

It felt more like a taxing bootcamp than a ticket to enlightenment.

On the Australian leg of her international book tour in March, Okrant told Weekend: "There is no best life, that is a fantasy."

But Okrant's gentle rebuke will have barely grazed the duco on the Oprah juggernaut, compared with the broadside fired in April by celebrity biographer Kitty Kelley.

Her controversial and unauthorised biography, Oprah, accused America's favourite agony aunt of vastly inflating stories about her childhood beatings and poverty, being so controlling as to not give her mother her private phone number and legally bullying those around her to obey oppressive privacy demands.

But if her ego is portrayed as gargantuan, so too is her heart.

Taking a less prominent but no less impactful place in Kelley's picture of a complex and compelling character is a catalogue of Winfrey's extraordinary good works.

Since 1998 she has donated a staggering $230 million towards her Oprah Winfrey Charitable Foundation, which supports charitable projects and provides grants to non-profit organisations around the world. Winfrey gave $43 million to her foundation in 2007 alone.

She is said to donate more of her own money to charity than any other US celebrity, and was the first black woman listed by Business Week among America's top 50 more generous philanthropists.

After Hurricane Katrina she raised more than $11 million for relief efforts, $10 million of which was her own money.

In the US she has helped more than 250 African-American men to continue or complete their education at Morehouse College in Atlanta, Georgia.

And, having fallen in love with South Africa, she spent $40 million setting up her Oprah Winfrey Leadership Academy for Girls outside Johannesburg (a school she was later forced to defend after a damaging sex scandal).

Kelley calculates that between 2003 and 2007 Winfrey donated almost $6 million to other South African AIDS-fighting, child-protection and educational organisations.

Despite an introduction peppered with allegations about how controlling Winfrey is of staff and information, and how unco-operative she was in the writing of the book, Kelley declared that she found her an inspiration.

Even so, she implied Winfrey is driven by darker demons even than the many she has shared on air.

In hundreds of interviews with Winfrey's family members, childhood and adult friends, former colleagues and boyfriends, Kelly found much to praise: her generosity, advocacy for women and children, and stand on sexual abuse.

But she says she found a "hugely complicated and contradictory" woman; someone "sometimes generous, magnanimous and deeply caring. Sometimes petty, small-minded and self-centred".

"She has done an extraordinary amount of good and also backed products and ideas that are not only controversial but considered by many to be harmful."

Having been denied a face-to-face meeting or any other contact with the star, Kelley catalogued every interview Oprah did in her 25-year slog to the top. She announced that this made Winfrey herself by far her "best source".

Of the larger-than-life personality that has transfixed a generation of American women, she concluded: "There is a warm side to Oprah and a side that can only be called as cold as ice."

And in the following 500 pages she painted the woman synonymous with her theme song, I'm Everywoman, not as the universal girlfriend we know and love, but as a vain and damaged diva, and hard-core materialist.

Australian audiences are about to get the chance to make their own minds up about the charismatic Winfrey when John Travolta flies her and her audience into Sydney on December 14.

We are ready to be wowed by the famous flair, warmth and charm of the pioneer of "change your life" TV.

But according to Kelley, we should also look beyond the inviting openness.

In one of her harsher assessments, the author accuses Winfrey of manipulating her audience by strategically drip-feeding personal information - her story of being so poor as a child she had cockroaches for pets and corncobs for dolls, her childhood sexual abuse, her lost baby and her early-career drug abuse - only at ratings times and only for professional gain.

But of all Kelley's revelations, perhaps most painful for the star would have been the words from the man who raised her as a father.

If Kelley's research is to be believed, it was the God-fearing Vernon Winfrey and his second wife, Zelma, who turned Oprah's troubled young life around.

When Oprah Winfrey was born in Mississippi in 1954, Vernon's then wife, Vernita Lee, told him he was the father.

Much later, when Lee declared the 14-year-old's promiscuity and truancy were too hard to handle, Vernon and his second wife, Zelma, agreed to take Oprah back into their care.

The Nashville barber stood by Oprah when she had a baby son just after her 15th birthday (who died soon after birth), and gave her the strict discipline that he felt she required to make something of her life.

Oprah has conceded she was an extremely challenging teen.

"I guess you could call me troubled, to put it mildly," she has said. And according to Kelley, who was given access to an autobiography the star wrote but pulled from publishing at the last minute believing it was too revealing, she described herself as a teen "prostitute".

WHILE Kelley believes this description is too harsh, she concedes that the troubled young Oprah did trade money for sex while living in her mother's home in Milwaukee.

Although Winfrey has long since brought many of her teenage tribulations into the open, on air, the verdict Vernon Winfrey passed on her behaviour as a girl must surely have been painful.

"She may be admired by the world, but I know the truth. So does God and so does Oprah," he told Kelley in face-to-face interviews. "Two of us remain unashamed."

He said his daughter, who has said in interviews "I am the instrument of God, I am his messenger and my show is His ministry", is still haunted by a raft of yet-to-be acknowledged "dark secrets".

Katherine Carr Esthers, the cousin Oprah Winfrey refers to as Aunt Katherine, was no less candid. She accused Winfrey of lying about her dire childhood, her daily beatings by her grandmother, her neglect and dirt poverty.

She says Oprah was doted upon in her first six years of life, when she lived as an only child with her mother in her grandmother's Mississippi home.

"Where Oprah got that nonsense about growing up in filth and roaches I have no idea," she told Kelley in three days of interviews.

"Now you have to understand I love Oprah, and I love all the good work she does for others, but I do not understand those lies that she tells.

"I've confronted her and asked, 'Why do you tell such lies?', Oprah told me,

'That's what people want to hear. The truth is boring, Aunt Katherine. People don't want to be be bored. They want stories with drama'."

IN THE highest level of the celebrity stratosphere, occupied by Oprah Winfrey, giving interviews is no longer required.

Although Kelley quotes Winfrey as saying interviews provided "the therapy I never had", the star has long since ceased to give them.

According to Kelley, what contact she grants is managed via emails to publicists, who return a series of standard replies.

Kelley asked repeatedly for a face-to-face meeting; and since Tourism Australia announced in September that taxpayers will pay upwards of $2.7 million to fly Oprah and 300 of her fans to Sydney, the Herald Sun has lodged many similar requests.

But Winfrey has remained tight-lipped.

Other than saying in passing that her best friend, Gayle King, had had a tough time when Kelley's book came out, her only remark on this year's furore has been "this too shall pass".

Nor did she talk to the press after announcing next year's season of her 25-year-old talk show would be her last, as she moves on to create her own television venture, the Oprah Winfrey Network.

In the absence of interviews, many commentators writing about the move again had no choice but to refer to the freshest source of information, Kelley's book.

Though it has been deemed in the US to have had little effect on the near-religious fervour of Winfrey's millions-strong army, it has lifted the lid on one of the most enigmatic TV legends of our time.

There is still the promise, though, that Oprah's millions of loyal fans will one day read her own, uncensored story in her own words.

As the New Yorker's Lauren Collins noted when Kelley's tell-all came out in April: "Since she was 15 years old, she has kept a diary. In 1993, she came very close to releasing an autobiography, which she cancelled just 14 weeks before its intended release.

"Publish it, Oprah. It would be your best life yet."