Across the country, South Africans already have begun honoring Mandela, who died Thursday at age 95, and officials expect tens of thousands to participate in next week's official services.
In their first statement since Mandela's death, his family said they had "lost a great man," just as they had when South Africa's apartheid government imprisoned him for decades.
"The pillar of our family is gone, just as he was away during that 27 painful years of imprisonment, but in our hearts and souls he will always be with us," said the statement, read by family spokesman Lt. Gen. Themba Templeton Matanzima.
"His spirit endures. As a family we commit ourselves to uphold and be guided by the values he lived for and was prepared to die for," he said.
At Mandela's house in the Johannesburg neighborhood of Houghton, more than 100 people, black and white, gathered in the morning where they sang liberation songs and homages to Mandela. Children danced to the singing from the swaying crowd as hawkers nearby sold Mandela regalia.
President Barack Obama said the former South African president "no longer belongs to us - he belongs to the ages."
Former Secretary of State Colin Powell, who spent time with Mandela over the years, told "CBS This Morning" Friday that the former South African president taught him many life lessons.
"Humility. Have a purpose. Have a vision. Be prepared to sacrifice. Be prepared to listen to the other side." And, said Powell, "always be ready to change your mind, but never abandon your principals."
"(Mandela was) a great, great boss to have," Bono said. "If you're going to be told what to do, let it be Nelson Mandela."
In a church service Friday in Cape Town, retired archbishop Desmond Tutu and fellow Nobel Peace Prize laureate said Mandela would want South Africans themselves to be his "memorial" by adhering to the values of unity and democracy that he embodied.
"All of us here in many ways amazed the world, a world that was expecting us to be devastated by a racial conflagration," Tutu said, recalling how Mandela helped unite South Africa as it dismantled apartheid, the cruel system of white minority rule, and prepared for all-race elections in 1994. In those elections, the anti-apartheid leader who spent 27 years in prison, became South Africa's first black president.
Among those who have already indicated that they will be travelling to South Africa to honor Mandela, who died at his Johannesburg home at the age of 95 on Thursday night, are Obama and his two predecessors, George W. Bush and Bill Clinton. Brazilian president Dilma Rousseff will also be among the guests.
Official services honoring Mandela begin Tuesday with a major memorial planned at FNB Stadium on the edge of Johannesburg's Soweto township. Government Minister Collins Chabane told journalists Saturday he expects massive crowds far beyond what the stadium's normal 95,000-person capacity could hold. He said there would be "overflow" areas set up.
"We can't tell people not to come," he said.
He couldn't offer specifics about how crowds would arrive there with all roads to the venue closed by police or who would serve as a master of ceremonies.
Those planning Mandela's funeral include the former president's family, the federal government, the military and the African National Congress political party. Despite some prior planning by authorities as Mandela grew frail and suffered bouts of hospitalization in recent years, many of the details remain up in the air.
It's unclear which ceremony world leaders will attend, either Tuesday's stadium memorial or the planned funeral service Dec. 15 in Qunu, the Nobel Peace Prize laureate's rural hometown in Eastern Cape Province. Chabane said South African officials briefed diplomats Saturday about the arrangements, though they would leave it to foreign governments to say which event their leaders would attend.
Mandela's body won't be at the stadium event Tuesday, Chabane said. His body will rest in state Wednesday, Thursday and Friday at the Union Buildings in Pretoria, the seat of government power in South Africa's capital.
Mourners will walk up the steps into the Union Buildings' amphitheater and file past Mandela's body, Chabane said. Authorities blocked visitors from visiting the amphitheater Saturday. Chabane said he didn't know yet whether it would be an open- or closed-casket viewing.
Mandela's body will be held overnight those days at a military hospital on Pretoria's outskirts, Chabane said. He called on residents to line the streets to serve as an honor guard as Mandela's body will pass twice each day.
ANC members will hold a ceremony on Dec. 14 at Waterkloof Air Force Base near Pretoria before Mandela's body is flown to Qunu from there, Chabane said.
Sunday has been declared a national day of prayer and reflection over Mandela's death. On Monday, South Africa's two houses of parliament will hold special sessions to pay tribute to Mandela, the country's first black and democratically-elected president.
Tributes to the former anti-apartheid activist continued to pour in from around the globe. Zimbabwean President Robert Mugabe, who has been in power since his country's independence from Britain in 1980 and supported Mandela's ANC during its struggle against the apartheid regime, paid his first public tribute to the deceased leader.
Despite himself being accused by critics of increasingly authoritarian rule, Mugabe praised Mandela as a champion of democracy and "an unflinching fighter for justice."
"Mr. Nelson Mandela's renowned and illustrious political life will forever remain a beacon of excellence," Zimbabwe's state-run newspaper The Herald quoted Mugabe as saying.
Hundreds gathered Saturday at Mandela's house in Houghton. They sang liberation songs and walked past expansive, stately homes carrying bundles of flowers and images of Mandela.
Precious Ncayiyana, a pharmacist, carried a painting of Mandela made from old newspaper clippings about him. His left eye bore the number 46664, Mandela's former inmate number, while his right eye said Madiba, his clan name.
Ncayiyana said she planned to drive the painting's artist to Pretoria so he could make a painting of the leader's body lying in state.
"It's my way of contributing to Madiba's legacy. He's gone, but his spirit lives on," she said.
As the chanting and cheering behind her grew louder, she raised her voice to add: "If you see someone you can help, it doesn't cost anything. ... That's what he taught us.