Barack Obama will make history lwhen he is sworn in as the 44th President of the United States - but what can we expect?
Tens of thousands of people - from around the world, as well as across the US - are expected to descend on the capital for the inauguration of America\'s first black leader.
Hotels in the capital are already fully booked, and preparations for the momentous occasion are in full swing.
Where - and when - does the inauguration take place?
Since 1801, the presidential inauguration ceremony has been held in the nation\'s capital, Washington DC. Before then, it took place in New York City.
Traditionally, the incoming Vice President and President take the oath of office on the steps of the United States Capitol, allowing members of the public to watch. However, if the weather is particularly bad, it can be held inside the building.
A special wooden \'inauguration platform\' is built for the ceremony. It will hold 1,600 people.
The inauguration takes place on January 20 of the year following the presidential election. The event begins at 11.30am, local time, with the swearing-in itself taking place at about noon.
Who attends the inauguration?
Traditionally, the outgoing President and First Lady are among those to watch as the new leader is sworn in.
Others on hand for the ceremony are members of the US Senate and the House of Representatives, cabinet members and nominees, the Justices of the Supreme Court, and state Governors.
All living former Presidents are also expected to attend.
Because of the historic nature of Barack Obama\'s election victory, record numbers of \'ordinary\' people are expected to try to attend the ceremony.
Admission to the inauguration is by ticket only.
Tickets are handed out by Senators and members of the House of Representatives, and are traditionally free; however the huge interest in this year\'s ceremony means many are being sold on by touts.
Members of the public will be able to watch the swearing-in on big screens lined up along the National Mall in Washington DC.
During the ceremony, both the President and Vice President will be sworn in.
The event will be marked with music, prayers and readings.
Singer Aretha Franklin, and musicians Itzhak Perlman and Yo-Yo Ma are expected to add some extra glamour this year, performing a selection of music arranged by star composer John Williams.
The US military also plays a major role in the ceremony, with parades, salutes and marching bands.
What does the incoming Vice President say?
The Vice President-elect\'s oath reads: "I do solemnly swear that I will support and defend the Constitution of the United States against all enemies, foreign and domestic, that I will bear true faith and allegiance to the same: that I take this obligation freely, without any mental reservation or purpose of evasion, and I will will and faithfully discharge the duties of the office on which I am about to enter."
Once the Vice President has been sworn in, a military band plays Hail Columbia - the first, unofficial, national anthem of the United States, and the entrance march for the Vice President.
What does the incoming President say?
According to the United States Constitution, the President-elect declares: "I do solemnly swear that I will faithfully execute the office of President of the United States, and will to the best of my ability, preserve, protect and defend the Constitution of the United States."
Some presidents also choose to add the words "so help me God" after the oath of office, following the example of George Washington, who also kissed the Bible.
Theodore Roosevelt, the 26th US President, added the phrase "and thus I swear", rather than using the religious line.
Barack Obama is expected to swear on the Lincoln Bible at the ceremony, though there is no rule which states a Bible - or any other text - must be used.
Presidents may \'affirm\' rather than \'swear\' if they wish, but only one - Franklin Pierce - is known to have done so.
The oath of office is traditionally administered by the US Chief Justice of the Supreme Court - currently John G Roberts.
What happens next?
To mark the presidential inauguration, a military band then plays Hail to the Chief, the official march of the US President.
This is followed by a 21-gun salute.
Can we expect a speech from Obama?
Yes. After he is sworn in, the new President traditionally makes an inaugural address, at which he outlines his plans for the future, offering a glimpse of the direction his administration will take in the months and years to follow.
What happens after the ceremony?
The official inauguration concludes with the US\'s national anthem.
Once the ceremony is over, the outgoing President and First Lady leave the White House for the last time, to begin their post-presidential lives.
The new President and Vice President, and their guests then attend a special lunch inside the Capitol building.
Later (at 2.30pm, local time), the US armed forces and others take part in the inauguration parade, in which marching bands, military regiments, and floats process from the Capitol, along Pennsylvania Avenue, to the White House.
The President and Vice President, and their families are expected to lead the parade as it makes its way through Washington DC, watched by thousands of people.
Is there an \'inauguration party\'?
A string of inauguration balls and galas will be held in Washington on and around the big day.
Barack Obama and Joe Biden are expected to attend ten parties on January 20 alone, each recognising a different group, from young people to the military, to those from the new president and vice-president\'s home states.
Are any other events planned?
Yes. Traditionally, a week of celebrations is held to mark the inauguration, with some festivities in the run-up to the swearing-in and others after the new president takes office.
This year, events will kick off with the arrival - by train - of Barack Obama, Joe Biden and their families in Washington DC on Saturday January 17.
The following day, Sunday January 18, an official welcome - open to the public, and certain to draw huge crowds - will take place on the steps of the Lincoln Memorial.
Monday January 19 is Martin Luther King Jr Day. The Obama and Biden families are expected to join in events marking the civil rights activist\'s legacy.