* Day honors Martin Luther King's commitment to service
* Volunteerism on rise in United States
* Obama also rolls his sleeves up
By Deborah Charles
WASHINGTON, Jan 19 (Reuters) - From sprucing up hiking trails to painting schools, Americans across the country, including President Barack Obama and his family, took part in a national day of service on Saturday to help kick off presidential inauguration ceremonies.
The day honors the slain civil rights leader Martin Luther King Jr., who famously said, "Life's most persistent and urgent question is: 'What are you doing for others?'" Obama will be publicly sworn in for a second term on Monday, which is also a national holiday honoring King.
Before his first inauguration in 2009, Obama urged Americans to spend part of Jan. 19 helping others by volunteering. This year, the Presidential Inaugural Committee asked people both to volunteer on Saturday and pledge to do more service work throughout the year.
Obama and his wife, Michelle, accompanied by their daughters, Malia and Sasha, rolled up their sleeves to spruce up an elementary school in Washington. After varnishing some bookshelves, both Obamas spoke to about 300 other volunteers and noted the importance of getting young people to get in the habit of helping out.
"I want to say thank you to the parents, for showing early on to all our young people how gratifying, how fulfilling this is," Obama said. His wife added, "We're passing on the baton to you all."
Beau Biden, the son of Vice President Joe Biden, and Chelsea Clinton, daughter of former President Bill Clinton, helped launch a volunteer fair on Washington's National Mall.
"The national day of service is a wonderful way to honor the legacy of Doctor King, to kick off this inaugural weekend," said Biden, the attorney general of Delaware and an Iraq war veteran.
"Despite all the talk of how divided we are as a nation, more and more Americans are coming together to serve each other every day. Volunteerism in America is at a five-year high," Biden said, noting that Americans spent 8 billion hours giving back to their communities in 2011.
Service projects were set up in all 50 states, and the inaugural committee offered links online to find projects ranging from clearing invasive plants from a hiking trail to feeding the hungry to putting together packages for U.S. troops overseas.
Sharon Mudd, a high school English teacher in Maryland, went to the National Mall to get some ideas for her students.
"I want to make sure that they realize that with privilege comes responsibility," she said.
Memona and Huda Shahid, 17-year-old twins from Chicago, were at the National Mall as part of a high school trip to Washington.
"As young adults, you get experience volunteering. For example, we want to study medicine, so we volunteered in a hospital," said Memona. "The important thing - when you volunteer do it from the heart." (Editing by Alistair Bell and Peter Cooney)