''You're going to be famous,'' Billie Holiday once told her, ''. . . (and) you better start asking yourself right now, 'When I get famous, who can I trust?' ''
''. . . Just take care of your son. Keep him with you and keep on telling him he's the smartest thing God made.''
That advice was given more than 20 years ago. Today, Maya Angelou is undeniably famous - as a dancer (premiere dancer with the US State Department-sponsored international touring company of ''Porgy and Bess''); poet (author of three collections of published verse); actress (nominated for a Tony on Broadway); playwright (she also wrote the screenplay and score when her play ''Georgia, Georgia'' was made into a movie); producer (writer and producer of a 10-part television series on African traditions in American life); director (one of the few women members of the Directors Guild of America); and civil rights activist (appointed by former President Carter to the commission on International Women's Year).
But with all these accomplishments, it's her relationship with her son, Guy, that Maya Angelou likes to talk about most.
''So often Guy was the only black kid in school in the areas in which we lived, and I would go to his school all the time,'' she recalled in a recent interview. ''I joined the PTA, and I'd bring cakes, and even sweep up the crumbs , because I didn't know what to say to the other mothers. I was young and I wore outrageous outfits - Hawaiian dresses, beads, and sandals. I was very dramatic.
''Guy was fighting for his own place in the sun, but I controlled the money and his hours to be out, and so I controlled his freedom. Since he had to control something, he began to try to control the way I dressed.
''Finally, one day he said to me, 'Mom, could you just not come to school unless they call for you? And if you do have to come, could you just wear a skirt and sweater?' ''
In her recently published book, ''The Heart of a Woman'' (New York: Random House), Miss Angelou writes about the growing-up years with Guy. This fourth volume in the autobiographical series that began with ''I Know Why the Caged Bird Sings'' takes mother and son from a California houseboat commune in the 1950s to the arts and politics of 1960s New York, and on to foreign adventures in Egypt and Ghana.
Along the way Miss Angelou joins the Harlem Writers' Guild, becomes Martin Luther King's program coordinator for the Southern Christian Leadership Conference after organizing a benefit cabaret for the SCLC, stars in a production of Genet's ''The Blacks,'' and leads a demonstration at the United Nations after the assassination of Patrice Lumumba in the Congo. There are encounters with Billie Holiday, Godfrey Cambridge, Shelley Winters, Bayard Rustin, and Malcolm X, and a turbulent, short-lived marriage to Vusi Make, a black South African nationalist.
''The Heart of a Woman'' tells what it's like for a single parent to raise a black child in the United States. It's also the story of one woman's search for love and courage. The fact that she finds both in her personal life, as well as in front of the lights, is evident on the opening page: ''I dedicate this book to my grandson, Colin Ashanti Murphy-Johnson.''
Miss Angelou ''tells all'' in straightforward, often self-deprecating, sometimes earthy prose. In her previous books she has talked candidly about her sojourn through the X-rated side of America. In ''The Heart of a Woman,'' Miss Angelou begins to assume more responsibility for her son, and we see an intelligent and determined nightclub singer rise to prominence as one of today's leading female authors and activists.
''I try to write about the issues I do with humor,'' she explains, ''because if you don't laugh, you'll die - you'll just shrivel up on the vine. I try to write about opposing gravity by getting up, again and again, no matter what knocks you down.''
Perhaps because she's been getting up all her life, Miss Angelou carries success at a healthy distance, like a played-out fish on the end of a long bamboo pole. There's no pretension, no self-consciousness, no holding back.
''I seem to have an open face,'' she says, ''so people always talk to me.''
She tells about an experience years ago, when she was on her way to Yale University for a speaking engagement. She got on a bus where the only available seat was next to a disgruntled-looking white woman. Eventually the woman rearranged her parcels and made room for Miss Angelou.
''I sat there, working a crossword puzzle, for quite a while,'' she recalls. ''Finally, the woman turned to me and said, 'You know, I want to tell you something. My daddy never hated you people. He said you all really could sing.'
''She told me she was from West Virginia, and then she just started to talk. Suddenly she felt that she could say anything to me, and she began to act out and speak out the most bizarre fantasies.
''Finally, she fell asleep, and it was evening when the bus reached New Haven. As I was getting off the bottom step, the woman awakened and began screaming, 'Colored girl! Colored girl!'
''I started to walk away, and then I thought, no. So I said, 'Are you calling me?'
''And she said, 'Yes. I wanna take you home with me - you just so sweet.' ''
Miss Angelou hoots with laughter at the remembered incident. ''Now if I had been a different person, I would have frozen her out from the start. But I sensed that she was more ignorant and needful than malicious. She didn't mean to be nasty, she hadn't even considered it. And I felt for her.''
She grins. ''Besides, she gave me plenty of material to use in my lecture that night on the black woman as myth.''
With four volumes of autobiography completed and more still to come, writing is now her full-time profession. But the publication of each new book brings her out of self-imposed solitude for the traditional round of publicity interviews and for some not-so-conventional appearances, as well.
One recent rainy evening found some 400 admirers crowded into an auditorium at the Boston Public Library to listen to her stories and hear her poetry. After 15 minutes of readings that kept breaking into impromptu dancing and blues singing, Miss Angelou said she was finally ready to talk. ''I know you're prepared,'' she told her audience, ''because I see you've brought sandwiches . . . just let me warn you that I've been known to answer questions I didn't even understand.''
The questions that followed touched not so much on her accomplishments as her personal life. These were friends who had met her in her writings and wanted to know her better. What was her son, Guy, doing these days? (''He's a fine man, an excellent poet, a social worker, and the father of my wondrous grandson.'') Had she kept in touch with Guy's father? (''No, and that poor fellow is lessened by not knowing his son.'')
There were questions, too, about an experience that Miss Angelou describes in the first volume of her autobiography - being raped at the age of 7.
''Rape is a violation that I don't think anyone yet has really dealt with,'' she says. ''It's an assault against all of us, against our species, not our gender. You know, I have 15 honorary degrees, I speak and can teach in six languages. I'm a Chubb fellow at Yale, I have a marvelous son, I'm fairly successful, and yet not one day has passed that I haven't remembered that rape.''
It's a moving hour, and when Miss Angelou tries to bring it to a close, they won't let her go. One standing, cheering ovation follows another, and she agrees to do one more verse of her poem ''And Still I Rise.''
Later, she reflects on the evening. ''I'm at once flattered,'' she begins, ''but at the same time, if people care that much about a stranger, it speaks more about the people than the stranger. I don't know how other performers feel, but I never feel that I've said enough or given enough.''
''In the last 10 years,'' she continues, ''I must have had a thousand letters from women who have been raped, and who have somehow been influenced by the way I've tried to look at the experience. Fortunately, they have been able to forgive themselves, which is the terrible cross that more often than not is lashed to the backs of the victims of rape.''
Maya Angelou is full of surprising forgiveness, rather than the bitterness that could have been the lasting result of her early childhood. Raised by her paternal grandmother in the dusty town of Stamps, Ark., she has memories of times when night riders of the Ku Klux Klan drove the family to hide their crippled uncle in the vegetable bins of their country store, under layers of onions and potatoes, for fear of the Klan's drunken lynchings.
She saw the fingers of cotton pickers cut by ''mean little cotton bolls,'' endured the taunts of ''po white trash'' children, and was often teased by other black children for being ''a too-big Negro girl, with nappy black hair, broad feet, and a space between her teeth that would hold a No. 2 pencil.''
But with the cruel and unjust days came nights of prayer meetings and hallelujah choruses at the Colored Methodist Episcopal Church of Stamps. In a particularly lyrical message in ''The Heart of a Woman'' Miss Angelou describes the roots of her faith:
We demonstrated the teachings of Christ. We turned other cheeks so often our heads seemed to revolve on the end of our necks. . . . Our church music showed that we believed there was something greater than we, something beyond our physical selves, and that that something, that God, and His Son, Jesus, were always present and could be called ''in the midnight hour'' and talked to when the ''sun raised itself to walk across the morning sky.'' We could sing the angels out of heaven and bring them to stand thousands thronged on the head of a pin. . . . Oh, there was no doubt that we were spiritual.
What is her concept today of God and her fellow man?
''I trust in the power of love, but I rarely speak of it,'' she replies, ''because oftentimes I would lose the listener who thinks he is sophisticated - and by sophisticated, he means that he only believes in those things seen and heard. So I know there may be a better way to reach him, and I say that I'm a Christian, that I blow it all the time, but I'm serious about it. And then if I really win him, I can slip in something about the things of the spirit.
''I know that God loves me,'' she continues, ''and that enables me to do anything, to try anything - anything good. I believe that Jesus Christ was the most courageous of persons because he dared to love. My land - to love! It asks everything!''
At so many key points in her life, related in ''The Heart of a Woman,'' Maya Angelou has come up against walls of indifference, even hatred, and has had to make a decision for or against nonviolence and love.
''I decided a long time ago that I would not indulge differences between human beings,'' she explains. ''I just don't have time. And I do not indulge fools lightly, either. I really try to come to grips with what is said, or their particular foolishness, because most of the differences have been set up for somebody else, at somebody else's whim, and for someone else's convenience. And I won't have it.
''As one of the creations of the Creator, I have respect for the other creations, and I wish that we were striving toward our potential. I suppose the saddest I ever am is when I'm brought face to face with one or more of us not striving at all.
''On the other hand, the least thing, the least smile or kindness, can just send me soaring in gratitude.''