"There is no reason to lose heart," she told thousands outside the headquarters of her political party in Rangoon.
Ms Suu Kyi was released by the military when her sentence ended on Saturday.
World leaders and human rights groups have welcomed her release. She had spent 15 of the past 21 years either under house arrest or in prison.
US President Barack Obama welcomed her release as "long overdue", while UN Secretary General Ban Ki-moon said Ms Suu Kyi was an "inspiration", and urged Burma to free its 2,200 political prisoners.
Aung Sang Suu Kyi had to struggle through the throngs of jubilant supporters to reach the podium where she was supposed to speak. Thousands had gathered to hear her.
They were probably expecting Ms Suu Kyi to make clear what she planned to do now that she was free - in the event she asked for help. She said she could not do it alone, and was "ready to work with all democratic forces" - an appeal perhaps to an opposition bitterly divided over the recent election here to unite once more.
She told the crowd she believed in the rule of human rights and the rule of law and felt no antagonism to those who had kept her detained for much of the past two decades. The basis of democratic freedom, she said, was freedom of speech. But she cautioned that if her supporters wanted to get to where they wanted, they had to do it the right way. "Do not give up hope," she added.
Ms Suu Kyi's words were measured and careful, she will know that the military leaders who rule this country will be scrutinising her every move and today she was careful not to provoke them.
Ms Suu Kyi has told the BBC in her first interview that she is willing to meet Burma's leader, Senior General Than Shwe, to help work towards national reconciliation.
"I think we will have to sort out our differences across the table, talking to each other, agreeing to disagree, or finding out why we disagree and trying to remove the sources of our disagreement," she said.
"There are so many things that we have to talk about," she added.
Her release came six days after Burma held its first elections in 20 years, which was won by the biggest military-backed party, the Union Solidarity and Development Party (USDP), but widely condemned as a sham.
Ms Suu Kyi's now-disbanded National League for Democracy (NLD) won the last election in 1990, but was never allowed to take power. She has been under house arrest or in prison almost continually ever since.
On Saturday, lawyers said no conditions had been placed on her freedom. But it is not yet clear what political role she will be able to play.
(Ref: http://www.bbc.co.uk)
